Determination of trace mercury by solid substrate room temperature phosphorescence quenching method based on lead carboxymethyl cellulose (Pb(CMC)(2)) particles containing luminescent salicyl fluorones molecules

Luminescent particles of lead carboxymethyl cellulose (Pb(CMC)₂), which contains salicyl fluorones (THBF), Pb(CMC)₂-THBF, were synthesized by sol-gel method. Pb(CMC)₂-THBF can emit intense and stable solid substrate room temperature phosphorescence (SS-RTP) on filter paper. EDTA can chelate the Pb²⁺ in Pb(CMC)₂-THBF, causing it decompose into aqueous soluble components PbY²⁻, CMC⁻ and THBF, and these components can react with Hg²⁺ to form (CMC)₂Hg-THBF, causing decrease of phosphorescence intensity. Based on the facts above, a new method for the determination of trace mercury by SS-RTP quenching method was established. The linear range of this method is 2.0-40.0 fg spot⁻¹ (5.0-100.0 pg ml⁻¹) of Hg²⁺, with a detection limit (LD) of 0.26 fg spot⁻¹, and the regression equation of working curve is (fg spot⁻¹, 0.4 μl spot⁻¹), r = 0.9994. This method has been applied to the determination of trace mercury in water sample with satisfactory results. The mechanism of SS-RTP emission is also discussed.     

Determination of trace silver by solid substrate-room temperature phosphorescence quenching method based on double catalytic system of meta-nitrophenyfluorone-polyoxyethylene-chromium-potassium bromate-beta-cyclodextrin

A new solid substrate-room temperature phosphorescence (SS-RTP) quenching method for the determination of trace silver has been established. It is based on the fact that when using Mg(2+) as ion perturber and beta-CD as surfactant, the system of meta-nitrophenyfluorone (R)-polyoxyethylene-Cr(III) can emit strong and stable room temperature phosphorescence signal on filter paper whose surface is modified by polyvinyl alcohol (PVA)-H(3)BO(3)-NaOH. Ag(I) can catalyze KBrO(3) oxidizing R-PEO-Cr(III) system which causes the quenching of SS-RTP. The reducing value of phosphorescence intensity (DeltaI(p)) is directly proportional to the concentration of Ag(I) in the range of 3.2-160 ag spot(-1) (corresponding concentration: 2.43 fg ml(-1), the sample volume: 0.40 microl spot(-1)) with a detection limit (LD) of 0.97 ag spot(-1). The regression equation of working curve can be expressed as DeltaI(p)=13.92+0.3089m(Ag)+ (ag spot(-1)) (r=0.9983, n=6). This method has many advantages, such as a wide linear dynamic range, high sensitivity, good repeatability and selectivity. It has been applied to the determination of trace silver in real samples with satisfactory results. What is more, the mechanism of SS-RTP quenching method based on Ag(I) catalyzing KBrO(3) oxidizing meta-nitrophenyfluorone has also been discussed.     

Determination of trace copper by solid substrate-room temperature phosphorescence quenching method based on activating effect of alpha,alpha'-dipyridyl on Vitamin C reducing beryllon

A new solid substrate-room temperature phosphorescence quenching method for the determination of trace copper has been established. It is based on the fact that beryllon (R) can emit strong and stable solid substrate-room temperature phosphorescence on the filter paper, and Vitamin C (Vc) reduces R to non-phosphorescent compound that leads to solid substrate-room temperature phosphorescence (SS-RTP) quenching of R, and alpha,alpha'-dipyridyl can activate copper catalyzing Vitamin C reducing R. The DeltaI(p) of the system with alpha,alpha'-dipyridyl is 3.3 times higher than that without alpha,alpha'-dipyridyl, which shows the reaction of alpha,alpha'-dipyridyl activating copper catalyzing Vitamin C reducing R. The reducing value of phosphorescence intensity (DeltaI(p)) is directly proportional to the content of Cu(II) in the range of 0.040-4.0 fg spot(-1) (corresponding concentration: 0.10-10.0 pg ml(-1), sample volume: 0.40 microlspot(-1)). The regression equation of working curve can be expressed as DeltaI(p)=69.99+41.00 m Cu(2+) (fg spot(-1)) (r=0.9980, n=6), and the detection limit is 0.0088 fg spot(-1)(corresponding concentration: 2.2 x 10(-14) g ml(-1)). This sensitive and accurate method with good repeatability and high selectivity has been applied to the determination of trace copper in real samples with satisfactory results. The reaction mechanism for the determination of trace copper by solid substrate-room temperature phosphorescence quenching method based on the activating effect of alpha,alpha'-dipyridyl on Vitamin C reducing beryllon is also discussed.     

蒽醌衍生物在痕量汞固体基质室温燐光猝灭法测定中的应用

该文合成了2,3-二氢-9,10-二羟基-1,4-蒽醌(R),并借助核磁共振谱、红外光谱、质谱及紫外光谱等方法确定其结构.基于R在醋酸纤维素膜固体基质上能产生强而稳定的固体基质室温燐光(SS-RTP),α,α'-联吡啶可活化Hg2+催化H2O2氧化R转化成无燐光化合物,导致固体基质室温燐光急剧猝灭,建立了催化H2O2氧...     

Determination of trace lead by solid substrate room temperature phosphorescence enhancing method based on heavy atom effect and dissoluble manganese supramolecule containing rhodamine 6G luminescent particles

Dissoluble manganese supramolecule containing rhodamine 6G luminescent particles (M2) are synthesized, based on dissoluble manganese supramolecule (M1) doping rhodamine 6G (R.6G), by crystalline method. The particle diameters of M1 and M2 determined by ETM are both of micron degree. M1 and M2 can emit solid substrate room temperature phosphorescence (SS-RTP) on filter paper. The transition probability from the singlet state (S1) to triplet state (T1) of the luminescent molecules was greatly enhanced, based on the increment of luminescent molecules for each spot and the heavy atom effect of certain amount of Pb2+. As a result, the phosphorescence intensity (Ip) of M2 was increased sharply, and the enhancing value of phosphorescence intensity (DeltaIp) is directly proportional to the concentration of Pb2+. Thus, a new method of SS-RTP enhancing for the determination of trace lead is established based on manganese supramolecule containing rhodamine 6G luminescent particles. The linear range of this method is 0.0040-0.400 pg spot-1 of Pb2+ (corresponding concentration, 0.01-1.0 ng mL-1; sample volume, 0.4 microL spot-1), with a detection limit (LD) of 0.0011 pg spot-1 (corresponding concentration, 2.8x10(-12) g mL-1 of Pb2+, n=11). For the working solutions containing 0.0040 and 0.40 ng mL-1 of Pb2+, they were determined repeatedly for seven times, respectively. The R.S.D.s were 3.2 and 3.8%, respectively. This method has good repeatability, sensitivity and high precision. It has been applied to the determination of trace lead in human hair and tea samples with satisfactory results.     

Determination of trace selenium by solid substrate-room temperature phosphorescence enhancing method based on potassium chlorate oxidizing phenyl hydrazine-1,2-dihydroxynaphthalene-3,6-disulfonic acid system

A new method for the determination of trace selenium based on solid substrate-room temperature phosphorimetry (SS-RTP) has been established. This method was based on the fact that in HCl-KCl buffer solution, potassium chlorate could oxidize phenyl hydrazine to form chloridize diazo-ion after being heated at 100 degrees C for 20 min, and then the diazo-ion reacted with 1,2-dihydroxynaphthalene-3,6-disulfonic acid to form red azo-compound which could emit strong room temperature phosphorescence (RTP) signal on filter paper. Selenium could catalyze potassium chlorate oxidizing the reaction between phenyl hydrazine and 1,2-dihydroxynaphthalene-3,6-disulfonic acid, which caused the sharp enhancement of SS-RTP. Under the optimum condition, the relationship between the phosphorescence emission intensity (DeltaIp) and the content of selenium obeyed Beer's law when the concentration of selenium is within the range of 1.60-320 fg spot-1 (or 0.0040-0.80 ng ml-1 with a sample volume of 0.4 microl). The regression equation of working curve can be expressed as DeltaIp=13.12+0.4839CSe(IV) (fg spot-1) (n=6), with correlation coefficient r=0.9991 and a detection limit of 0.28 fg spot-1 (corresponding to a concentration range of 7.0x10(-13) g ml-1 Se(IV), n=11). After 11-fold measurement, R.S.D. were 2.8 and 3.5% for the samples containing 0.0040 and 0.80 ng ml-1 of Se(IV), respectively. This accurate and sensitive method with good repeatability has been successfully applied to the determination of trace selenium in Chinese wolfberry and egg yolk with satisfactory results. The mechanism of the enhancement of phosphorescence was also discussed.     

Determination of Trace Titanium by Solid Substrate－Room Temperature Phosphorimetry with 4,5－Dibromophenylfluorone as Luminescent Ligand and Triton X－100 as Sensitizer

A new highly sensitive solid substrate room temperature phosphorimetry for the determination of trace titanium is proposed based on the sensitization of Triton X-100 to the SS-RTP intensity of 4, 5-dibro-mophenylfluorone-titanium complex adsorbed on the filter paper substrate modified by gelatin. When Triton X-100 was added into the luminescence system, the RTP intensity was raised 3 times stronger than that of the system without Triton X-100. The linear dynamic range of the new method is 0. 64 ～ 3.2 fg/spot (0. 4 μL) with a detection limit of 12.8 ag/spot, and the regression equation of the working curve is △Ip = 482. 0 119.5mTi（Ⅳ) (fg/spot), the correlation coefficient r= 0. 9992, n = 6. The phosphorescence lifetime (r= 0. 85 ms) was also determined. The recoveriesCand RSD) for the determinations of titanium in human hair and tea samples were 101.0% (3. 0%) and 99. 97% (4. 2%), respectively.     

Determination of trace tin by solid substrate-room temperature phosphorimetry using sodium dodecyl sulfate as sensitizer

The effects of different surfactants on solid substrate-room temperature phosphorescence (SS-RTP) properties of Sn(4+)-morin systems were investigated. It was found that the SS-RTP intensity of luminescence system was increased greatly in presence of sodium dodecyl sulfate (SDS). A new highly sensitive method for the determination of trace tin has been proposed based on sensitization of SDS on SS-RTP intensity of morin-tin system on the filter paper substrate. The linear dynamic range of this method is 8.0-112 ag per spot (with the volume of 0.4 microl per spot) with a detection limit of 4.0 ag per spot, and the regression equation is DeltaIp=199.7+3.456m(Sn(IV)) (ag per spot), with the correlation coefficient r=0.9998 (n=7). This simple, rapid and reproducible method has been applied to determine the amount of tin in real samples with satisfactory results.     

Deposition of silver nanoparticles on cellulosic fibers via stabilization of carboxymethyl groups

The stabilizing role of carboxymethyl groups on the conformal deposition of Ag NPs over cellulosic fibers was elucidated while developing a method for the deposition of silver nanoparticles (NPs) on cellulose acetate (CA), cellulose and partially carboxymethylated cellulose (CMC) electrospun fibers. CMC fibers were prepared through judicious anionization of deacetylated cellulose acetate fibers. Ag NPs were chemically reduced from silver nitrate using sodium borohydride and further stabilized using citrate. Ag NPs were directly deposited onto CA, cellulose and CMC electrospun fibers at pH conditions ranging from 2.5 to 9.0. The resulting composites of Ag/fiber were characterized by field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX). The results revealed that the amount of Ag agglomerates and NPs deposited on CMC fibers was higher than that deposited on cellulose fibers at similar pH conditions, and that barely any Ag agglomerates or NPs were deposited on the CA fibers. These results implied that functional groups on the cellulose backbone played two important roles in the deposition of NPs as follows: (1) Hydrogen bonding was the main driving force for agglomeration of NPs when the medium pH was below 4.4, which corresponds to the pKa of carboxylic acid groups; (2) Carboxymethyl groups could replace citrate groups as stabilizers allowing the fabrication of a uniform and evenly distributed Ag NPs layer over CMC fibers at higher pH values. This report also highlights the importance of the substrate’s surface charge and that of the pH of the medium used, on the deposition of NPs. The composite of Ag NPs on CMC electrospun fibers appears to be a promising candidate for wound dressing applications due to its superior antibacterial properties originated by the uniform and even distribution of Ag NPs on the surface of the fibers and the wound healing aptness of the CMC fibers.     

Determination of trace glucose and forecast of human diseases by affinity adsorption solid substrate room temperature phosphorimetry based on Triticum valgaris lectin labeled with 4.0-generation dendrimers

A new phosphorescence labeling reagent Triton-100X-4.0G-D (4.0G-D refers to 4.0-generation dendrimers) was found. Quantitative specific affinity adsorption (AA) reaction between Triton-100X-4.0G-D-WGA and glucose (G) was carried out on the surface of nitrocellulose membrane (NCM), and the DeltaI(p) of the product of AA reaction was linear correlation to the content of G. Based on the facts above, a new method for the determination of trace G was established by WGA labeled with Triton-100X-4.0G-D affinity adsorption solid substrate room temperature phosphorimetry (Triton-100X-4.0G-D-WGA-AA-SS-RTP). This research showed that AA-SS-RTP for either direct method or sandwich method could combine very well the characteristics of both the high sensitivity of SS-RTP and the specificity of the AA reaction. Detection limits (LD) were 0.24 fg spot(-1) for direct method and 0.18 fg spot(-1) for sandwich method, indicating both of them were of high sensitivity. The method has been applied to the determination of the content of G in human serum, and the results were coincided with those obtained by glucose oxidize enzyme method. It can also be applied to forecast accurately some human diseases, such as primary hepatic carcinoma, cirrhosis, acute and chronic hepatitis, transfer hepatocellular, etc. Meanwhile, the mechanism for the determination of G with AA-SS-RTP was discussed.     

Determination of trace gastrin and diagnosis of human diseases using CdTe quantum dots labelled gastrin antibodies as phosphorescence sensors

CdTe quantum dots (CdTe-QDs) can emit strong and stable room temperature phosphorescence (RTP) via the perturbation effect of a Pb(2+) ion on the surface of a nitrocellulose membrane (NCM). CdTe-QDs-Ab(GAS), the product of CdTe-QDs labelled gastrin antibodies (Ab(GAS)), can not only maintain good RTP characteristics, but can also be used as a RTP sensor and carry out highly specific immunoreactions with gastrin (GAS) to form GAS-Ab(GAS)-CdTe-QDs causing the ΔI(p) of the system to sharply enhance. Thus, a new solid substrate room temperature phosphorescence immunoassay (SSRTPIA) for the determination of GAS was established based on the linear relativity between the ΔI(p) of the system and the content of GAS. The limit of quantification (LOQ) of this method was 0.43 fg spot(-1) with the corresponding concentration being 1.1 × 10(-12) g mL(-1) and sampling quantity being 0.40 per spot(-1). This highly specific, accurate, selective and sensitive RTP sensor has been applied to the determination of GAS in biological samples and the diagnosis of diseases, and the results agreed well with those obtained by radioimmunometric assay (RIA). Meanwhile, the mechanism of SSRTPIA for the determination of GAS using CdTe-QDs-Ab(GAS) as the RTP sensor was discussed.     

Preparation for nitrocellulose membrane-poly (vinyl alcohol)-ionic imprinting and its application to determine trace copper by room temperature phosphorimetry

Nitrocellulose membrane-poly (vinyl alcohol)-ionic imprinting (NCM-PVA-I-I) was prepared using Cu²⁺ as template. The cavity in NCM-PVA-I-I matched Cu²⁺ very well and the selectivity was high. Cu²⁺ entered the cavity and then could form ionic association ([Cu²⁺]·[(Fin⁻)₂]) with the anion of fluorescein (Fin⁻) outside the cavity by electrostatic effect. [Cu²⁺]·[(Fin⁻)₂] could emit strong and stable room temperature phosphorescence on NCM-PVA-I-I. Its ΔI_p was proportional to the content of Cu²⁺. Based on the above facts, a new method for the determination of trace copper by solid substrate-room temperature phosphorimetry (NCM-PVA-I-I-SS-RTP, SS-RTP is the abbreviation of solid substrate-room temperature phosphorimetry) using NCM-PVA-I-I technique has been established. The linear range of this method was 2.00-144.00 fg Cu²⁺ spot⁻¹ (sample volume: 0.40 μL spot⁻¹, corresponding concentration: 5.00-360.00 pg mL⁻¹), and the detection limit calculated by 3Sb/k was 0.43 fg Cu²⁺ spot⁻¹ (corresponding concentration: 1.1 × 10⁻¹² g mL⁻¹, n = 11). Samples containing 2.00 and 144.00 fg Cu²⁺spot⁻¹ were measured, respectively, for seven times and R.S.D.s were 3.5% and 4.7%. NCM-PVA-I-I-SS-RTP could combine very well the characteristics of both the high sensitivity of SS-RTP and the high match and selectivity of NCM-PVA-I-I, and it was rapid, accurate, sensitive and with good repeatability. It has been successfully applied to determine trace copper in human hair and tea samples.     

Determination of trace formaldehyde by solid substrate-room temperature phosphorescence quenching method based on the rose bengal-potassium bromate-Tween-80 system

A new method for the determination of trace formaldehyde by solid substrate-room temperature phosphorescence quenching method has been proposed. It is based on the facts that rose bengal (R) can emit intense and stable room temperature phosphorescence on the solid substrate of filter paper (SS-RTP). Potassium bromate (KBrO(3)) can oxidize R, which causes the quenching of RTP. In the presence of HCHO, it can react with KBrO(3) to form Br(2) and Br(2) can oxidize R, which causes smart quenching of RTP. The phosphorescence intensity (DeltaI(p)) is directly proportional to the concentration of HCHO. In the presence of Tween-80, the DeltaI(p) will be increased to 9.1 times higher than that without it. The linear range of this method is 0.016-1.6fgspot(-1) (corresponding concentration: 0.040-4.0 pgml(-1), 0.40 microlspot(-1)) with the detection limit of 4.5agspot(-1) (corresponding concentration: 1.1 x 10(-14) gml(-1)). The regression equation for working curve is DeltaI(p)=136.6+28.28m(HCHO)fgspot(-1) (r=0.9935, n=6). This method is sensitive, simple, rapid and has been applied to the determination of trace formaldehyde in real samples with satisfactory results. The mechanism of determination of trace formaldehyde by SS-RTP quenching method based on the rose bengal-KBrO(3)-Tween-80 system is also discussed.     

Catalytic solid substrate-room temperature phosphorimetry for the determination of trace As(V) based on oxidising reaction between hydrogen peroxide and fullerenol using tween-80 as sensitizer

A new catalytic solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace arsenic(V) has been established. It is based on the fact that fullerenol (F-ol) emitted strong and stable room temperature phosphorescence (RTP) on nitric acid cellulose membrane (NCM) substrate. H₂O₂ could oxidise F-ol to cause the quenching of RTP. As(V) could catalyse H₂O₂ to oxidise F-ol and decrease the RTP signal of F-ol sharply. After adding tween-80 in the system, its ΔI _p enhanced 7.7 times compared with the without-tween-80 levels. Under the optimum conditions, the linear dynamic range of this method was 0.016?11.2 ag spot^?1 with a detection limit (LD) of 9.3 zg spot^?1 (corresponding concentration: 2.3 × 10^?17 g mL^?1). This sensitive, simple and selective method has been successfully applied to the determination of trace As(V) in human hair and tea samples. The reaction mechanism for SS-RTP is also discussed.     

以CdS量子点为荧光探针测定痕量铜

以羧甲基纤维素钠（CMC）为稳定剂,在水相中制备了CdS量子点,基于Cu2+离子对量子点荧光的猝灭作用,建立了定量测定Cu2+离子的新方法。 CdS量子点对铜离子呈现出高选择性,除Co2+和Hg2+离子外,其它常见金属离子的存在对铜的测定几乎不产生干扰。 考察了不同缓冲体系及缓冲液pH值、量子点浓度、反应时间和反应温度等因素的影响,确定了Cu2+离子的最佳分析条件,即pH=5.6,磷酸氢二钠-磷酸二氢钾缓冲溶液的浓度为0.033 mol/L,量子点的浓度为2.0×10-4 mol/L。 在最佳条件下,量子点的相对荧光强度与Cu2+离子的浓度呈很好的线性关系,该方法的线性范围为5.0×10-8~2.0×10-5 mol/L,线性回归方程为：F0/F=1.015 0+100 791.6c,检出限为8.0×10-9 mol/L。 本方法简单、快速,与文献报道的其它基于量子点荧光探针Cu2+离子分析方法相比,此法对Cu2+离子呈现出更高的选择性且具有更宽的线性检测范围。 将此法用于水样和人体头发等实际样品中Cu2+离子含量的测定,结果令人满意。     

以国产微晶纤维素膜作固体基质五种多环芳烃的室温磷光法研究

本文考察了10种国产纤维素膜用于多环芳烃固体基质室温磷光(SS-RTP)的可行性。实验表明:MN-C和MN-P两种型号的微晶纤维素膜用于多环芳烃的SS-RTP是适宜的。阴离子交换纤维素膜、CM-纤维素膜和聚酰胺-6膜也能诱导出多环芳烃的RTP来,但其性能逊于前两种。故本文应用MN-C和MN-P两种微晶纤维素膜基质考察了五种多环芳烃的RTP特征,并建立了它们的SS-RTP新方法。并与用滤纸作基质的实验结果进行了比较,表明两种新的固体基质的RTP性能优于滤纸基质。     

Metal adsorption of carboxymethyl cellulose/carboxymethyl chitosan blend hydrogels prepared by Gamma irradiation

Blend hydrogels based on the carboxymethyl cellulose (CMC) and carboxymethyl chitosan (CMCts) were prepared by γ-irradiation of a high concentrated CMC/CMCts aqueous solution. Properties of the hydrogels, such as gel fraction, swelling ratio, gel strength, and metal adsorption for Pb and Au were investigated. The gel fraction increased with increasing dose, while the swelling ratio decreased with increasing it. The obtained blend hydrogels had high adsorption performance which was controlled by adjusting the composition of CMC/CMCts.     

Two- and three-dimensional silver(I)-organic networks generated from mono- and dicarboxylphenylethynes

Three phenylethynes bearing methyl carboxylate (HL1), monocarboxylate (H(2)L2), and dicarboxylate (H(2)L3) groups were utilized as ligands to synthesize a new class of organometallic silver(I)-ethynide complexes as bifunctional building units to assemble silver(I)-organic networks. X-ray crystallographic studies revealed that in [Ag(2)(L1)(2)·AgNO(3)](∞) (1) (L1= 4-C(2)C(6)H(4)CO(2)CH(3)), one ethynide group interacts with three silver ions to form a complex unit. These units aggregate by sharing silver ions with the other three units to afford a silver column, which are further linked through argentophilic interaction to generate a two-demensional (2D) silver(I) network. In [Ag(2)(L2)·3AgNO(3)·H(2)O](∞) (2) (L2 = 4-CO(2)C(6)H(4)C(2)), the ethynide group coordinates to four silver ions to form a building unit (Ag(4)C(2)C(6)H(4)CO(2)), which interacts through silver(I)-carboxylate coordination bonds to generate a wave-like 2D network and is subsequently connected by nitrate anions as bridging ligands to afford a three-demensional (3D) network. In [Ag(3)(L3)·AgNO(3)](∞) (3) (L3 = 3,5-(CO(2))(2)C(6)H(3)C(2)), the building unit (Ag(4)C(2)C(6)H(3)(CO(2))(2)) aggregates to form a dimer [Ag(8)(L3)(2)] through argentophilic interaction. The dimeric units interact through silver(I)-carboxylate coordination bonds to directly generate a 3D network. The obtained results showed that as a building unit, silver(I)-ethynide complexes bearing carboxylate groups exhibit diverse binding modes, and an increase in the number of carboxylate groups in the silver(I)-ethynide complex unit leads to higher level architectures. In the solid state, all of the complexes (1, 2, and 3) are photoluminescent at room temperature.     

Determination of trace mercury by solid substrate-room temperature phosphorimetry based on catalytic effect of Hg(2+) on formation of the ion association complex [Fe(bipy)(3)](2+)[(FinBr(4))(2)](2-)

A new solid substrate-room temperature phosphorimetry method for the determination of trace mercury has been established. It bases on the fact that in acetic acid medium, Hg²⁺ ion can catalyze the substitute reaction of CN⁻ ligand in [Fe(CN)₆]⁴⁻ by 2,2′-bipyridyl (bipy), and the resultant [Fe(bipy)₃]²⁺ cation can react with FinBr₄⁻ anion of tetrabromofluorescein (HFinBr₄) to form ion association complex [Fe(bipy)₃]²⁺[(FinBr₄)₂]²⁻ which can emit phosphorescent signal on filter paper substrate. Under the optimum condition, the linear dynamic range of this method is 1.6-16 fg per spot with a detection limit (LD) of 0.18 fg per spot (0.4 μl sample solution per spot), and the regression equation of working curve is ΔI_p=1.058+7.671 C_Hg²⁺ (fg per spot ), n=7, correlation coefficient is 0.9990. This method has been applied to the determination of trace mercury in hair and cigarette samples with satisfactory result. The reaction mechanism for formation of the ion association complex is also discussed.     

Determination of human IgG by solid substrate room temperature phosphorescence immunoassay based on an antibody labeled with nanoparticles containing Rhodamine 6G luminescent molecules

Luminescent silicon dioxide nanoparticles (R-SiO2) with size of 50 nm containing Rhodamine 6G (R) were synthesized by sol-gel method. In the presence of Pb(Ac)2 as a heavy atom perturber, the particle can emit intense and stable room temperature phosphorescence signal of R, respectively, on polyamide membrane, with the lambda(ex)(max)/lambda(em)(max) = 470/635 nm for R. Our research indicates that the specific immune reaction between goat-anti-human IgG antibody labeled with R-SiO2 and human IgG can be carried on polyamide membrane quantitatively, and the phosphorescence intensity was enhanced after the immunoreactions. Thus, a new method of solid substrate room temperature phosphorescence immunoassay (SS-RTP-IA) for the determination of human IgG was established basing on antibody labeled with the nanoparticles containing binary luminescent molecules. The linear range of this method is 0.0624-20.0 pg spot(-1) of human IgG (corresponding concentration, 0.156-50.0 ng mL(-1); sample volume, 0.40 microL spot(-1)). The regression equations of working curves are delta I(p) = 88.16. + 16.79 m(IgG) (pg spot(-1)) (485/646 nm, r = 0.9997). Detection limits calculated by 3Sb/k are 0.017 pg spot(-1). For samples containing 0.156 and 50.0 ng mL(-1) of IgG, we measured repeatedly for 11 times, RSDs are 3.9 and 2.8%, respectively. This method is sensitive, accurate and of high precision.