Determination of Glucose by Affinity Adsorption Solid Substrate‐room Temperature Phosphorimetry Based on Triticum Vulgare Lectin Labeled with Silicon Dioxide Nanoparticle Containing Fluorescein Isothiocyanate

In the presence of heavy atom perturber Pb2＋, silicon dioxide nanoparticle containing fluorescein isothiocyanate (FITC-SiO2) could emit a strong and stable room temperature phosphorescence (RTP) signal on the surface of acetyl cellulose membrane (ACM). It was found in the research that a quantitative specific affinity adsorption (AA) reaction between triticum vulgare lectin (WGA) labeled with luminescent nanoparticle and glucose (G) could be carried on the surface of ACM. The product (WGA-G-WGA-FITC-SiO2) of the reaction could emit a stronger RTP signal, and the ΔIp had linear correlation to the content of G. According to the facts above, a new method to determine G by affinity adsorption solid substrate room temperature phosphorimetry (AA-SS-RTP) was established, based on WGA labeled with FITC-SiO2. The detection limit (LD) of this method calculated by 3Sb/k was 0.47 pg•spot－1 (corresponding to a concentration value 1.2×10－9 g•mL－1, namely 5.3×10－9 mol•L－1), the sensitivity was high. Meanwhile, the mechanism for the determination of G by AA-SS-RTP was discussed.     

Affinity Adsorption Solid Substrate‐Room Temperature Phosphorimetry for the Determination of Alkaline Phosphatase

Abstract

In the presence of Pb(Ac)₂, the silicon dioxide nanoparticle containing rhodamine 6G (R‐SiO₂) can emit strong and stable solid substrate‐room temperature phosphorescence (SS‐RTP) signal on the surface of acetyl cellulose membrane (ACM) at λ_ex/λ_em=482/649 nm. It was found in the research that specific affinity adsorption reaction between triticum vulgare lectin (WGA) (which was labeled with luminescent silicon dioxide nanoparticle) and alkaline phosphatase (AP) can be carried out on the surface of ACM. The product of the reaction can emit stronger SS‐RTP signal. A new method of SS‐RTP for the determination of AP was established, based on an affinity adsorption reaction between AP and WGA labeled with nanoparticles containing rhodanime 6G luminescent molecules. The linear range of this WGA‐AP‐WGA‐R‐SiO₂ method is 1.00–360.00 ag AP spot^?1 (sample volume: 0.40 µL spot^?1, corresponding concentration range: 2.50–900.00 fg mL^?1). The regression equation of working curve is ΔIp=16.24+0.8856 m_AP (ag spot^?1), r=0.9993. Detection limit of this method calculated by 3S_b/k is 0.14 ag spot^?1. After 11‐fold replicate measurements, RSD are 3.9% and 3.1% for the systems containing 1.00 and 360.00 ag AP spot^?1, respectively. Compared with R‐SiO₂‐WGA‐AP method (detection limit: 0.45 ag spot^?1, corresponding concentration range: 2.00–320.00 ag spot^?1), the sensitivity of WGA‐AP‐WGA‐R‐SiO₂ method was obviously improved and the linear range was wider. The sensitivity, accuracy, and precision of this method are high. It has been successfully applied to determine AP in human serum.     

№Determination of Trace Arsenic by Solid Substrate-Room Temperature Phosphorescence Quenching Method Based on the Catalyzed Reaction of H2O2 Oxidizing 9-Hyd roxy-2,3,4,9-tet rahyd ro-1,10-anth raquinone

A new solid substrate-room temperature phosphorescence （SS-RTP） quenching method for the determination of trace As（V） has been developed, based on the facts that 9-hydroxy-2,3,4,9-tetrahydro-1,10-anthraquinone （R） can emit intense and stable SS-RTP on solid substrate, and α,α＇-dipyridyl can activate As（V） catalysis of the reaction of H2O2 oxidizing R to non-phosphorescence compound R＇, which can cause the sharp quenching of SS-RTP. Under the optimum condition, the relationship between the ΔIp of the emitting intensity and 1.60-160 fg·spot^-1 As（V） （corresponding concentration： 0.0040-0.40 ng·mL^-1, sample volume： 0.4 μL·spot^-1） conformed to Beer＇ law. The regression equation of working curve can be expressed as ΔIp= 20.46＋0.5492CAs（v） fig·spot^-1） （r= 0.9995, n = 6）. The limit detection （LD） is 0.27 fg·spot^-1 [As（V） corresponding concentration： 6.8 × 10^-13 g·mL^-1, n=11]. The samples containing 0.0040 and 0.40 ng·mL^-1 As（V） were repeatedly determined for 11 times. RSD are 3.0% and 2.7% respectively. The SS-RTP mechanism was also discussed. R was synthesized in this paper. Meanwhile, the structure was determined by NMR, IR, mass spectra and elemental analysis.     

A New Fluorescein Isothiocyanate-Piperidine Self-ordered Ring Phosphorescent Probe for the Determination of Trace Protein

The ? COOH in fluorescein isothiocyanate (FITC) reacted with ? NH? in piperidine (P) to form FITC‐P on the center of indentation of polyamide membrane (PAM) when drying for 2 min at (92±1)°C. Then, the FITC‐P diffused outward from the indentation center and formed the round SOR‐P‐FITC (containing the FITC‐P self‐ordered rings). Thus, multi‐FITC accumulated on SOR‐P‐FITC, leading to the enhancement of RTP signal on bio‐target, whose I_p increased 2.0 times compared with non‐generated SOR. When bovine serum albumin (BSA) was added to the center of SOR‐P‐FITC, ? NCS of FITC in SOR‐P‐FITC reacted with ? NH₂ of BSA to form SOR‐P‐FITC‐BSA, which caused the RTP signal of FITC to enhance sharply. The ΔI_p of the system was 3.4 times higher than that without β‐CD and 4.0 times higher than that without SOR‐P‐FITC formed. Its ΔI_p was linear to the content of BSA. Therefore, a new solid substrate‐room temperature phosphorimetry (SS‐RTP) for the determination of trace protein was established using SOR‐P‐FITC as a phosphorescent probe. Under the optimum condition, the linear range of this method was 0.040–16.0 ag·spot^?1 with a detection limit (LD) of 8.5 zg·spot^?1 (0.40 µL sample solution per spot, the corresponding concentration was 2.1×10^?17 g·mL^?1), and the regression equation of working curve was ΔI_p=3.848+4.240m_BSA (ag·spot^‐1), n=6, correlation coefficient (r) was 0.9993. This method with high sensitivity had been applied to determining the content of trace protein in the water samples, and the results coincided well with those obtained with pyrocatechol violet‐Mo(VI) method (P.V.M.M.). At the same time, the mechanism of SS‐RTP using SOR‐P‐FITC as a phosphorescent probe (SOR‐P‐FITC‐SS‐RTP) was discussed.     

Solid Substrate Room Temperature Phosphorimetry for the Determination of Trace Mercury Based on the Reaction between Alkaline Phosphatase and Mercury Using Triton X-100 as a Sensitizer

A new solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace mercury has been established, using Triton X‐100 as a sensitizer. The regression equation of working curve was ΔI_p=11.40m(Hg²⁺)+1.569 (ag·spot^?1, n=6, ΔI_p=I_p1?I_p2, I_p1 and I_p2 referred to the phosphorescence intensity of the blank reagent and the test solution, respectively), and correlation coefficient (r) was 0.9984. The RSD valus of the determination of 0.016 and 8.0 ag·spot^?1 Hg²⁺ were 4.1% and 1.7% (n=8), respectively, indicating that the method had good repeatability. The limit of detection (LOD) calculated by 3Sb/k was 7.0 zg·spot^?1 Hg²⁺ (corresponding concentration: 1.8×10^?17 g·mL^?1, Sb=0.025, n=11). This method has high sensitivity, selectivity and precision, which was applied to determination of trace mercury in water samples with the result being agreed very well with that of dithizone extraction spectrophotometry.     

Strong Luminescence Catalytic Solid Substrate Room Temperature Phosphorescence for the Determination of Trace Copper

Under the conditions of reacting at 100°C for 8 min and irradiating with the infrared light for 15 min, methylene blue (MEB) could emit weak room temperature phosphorescence (RTP) on the cellulose acetate membrane (CAM) using Pb²⁺ as the ion perturber in the NH₃‐NH₄Cl (pH=9.80) solution. MEB was oxidized by H₂O₂, which caused the RTP of the system to enhance. Cu²⁺ could catalyze the reaction of H₂O₂ oxidizing MEB, which caused the RTP of the system to enhance sharply. The ΔI_p (I_p0?I_p, the I_p0 and I_p were RTP intensity of the blank reagent and RTP intensity of the test reagent, respectively) of the catalytic system was 133.6, which was 4.1 times larger than that without infrared light irradiation (33.1). Its ΔI_p was proportional to the content of Cu²⁺. Thus, a new catalytic solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace copper has been established. The limit of quantization (LOQ) of this method was 0.12 ag·spot^?1 (sample volume: 0.40 µL·spot^?1, corresponding concentration: 3.0×10^?16 g·mL^?1), showing high sensitivity. This method not only has been successfully applied to the determination of trace copper in the tobacco, tea and human serum, but also could predict human diseases. The catalytic reaction was first order reaction, whose activation energy (E) was 18.17 kJ·mol^?1 and rate constant (k) was 3.4×10^?4 s^?1. At the same time, the mechanism of catalytic SSRTP for the determination of trace copper was 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.     

Determination of trace alpha-fetoprotein variant by affinity adsorption solid substrate-room temperature phosphorimetry and its application to the forecast of human diseases

In the presence of ion perturber LiAc, 4-generation polyamidoamine dendrimers (4G-D) could emit strong and stable room temperature phosphorescence (RTP) signal at on nitrocellulose membrane (NCM), and Triton X-100 could sharply enhance the RTP signal of 4G-D. Triton X-100-4G-D was used to label concanavalin agglutinin (Con A) to get the labeling product Triton X-100-4G-D-Con A. Quantitative specific affinity adsorption (AA) reaction between Triton X-100-4G-D-Con A and α-fetoprotein variant (AFP-V) could be carried out on the surface of NCM, whose product Triton X-100-4G-D-Con A-AFP-V could emit strong and stable RTP and its ΔI_p was proportional to the content of AFP-V. According to the facts above, a new affinity adsorption solid substrate-room temperature phosphorimetry (AA-SS-RTP) for the determination of trace AFP-V by Con A labeled with Triton X-100-4G-D was established. Detection limits of this method were 0.23 fg spot⁻¹ (direct method, corresponding concentration: 5.8 × 10⁻¹³ g mL⁻¹) and 0.13 fg spot⁻¹ (sandwich method, corresponding concentration: 3.2 × 10⁻¹³ g mL⁻¹). It has been successfully applied to determine the content of AFP-V in human serum and forecast human diseases, for its high sensitivity, long RTP lifetime, good repeatability, high accuracy and little background perturbation with at the long wavelength area. Meanwhile, the mechanism for the determination of trace AFP-V using AA-SS-RTP was also discussed.     

A Novel Chemosensor for Fe(III) Based on Phosphorescence Quenched 9-Bromophenanthrene Induced by β-Cyclodextrin Combined with Flow Injection Renewable Drop

A novel phosphorescent chemosensor for Fe(III) based on room-temperature phosphorescence (RTP) using the method of flow injection renewable drop (FIRD) was developed. A RTP of 9-bromophenanthrene (BrP) can be induced by β-cyclodextrin (β-CD) in the presence of cyclohexane (CH); however, trace Fe(III) caused a decrease of the RTP emission. The optimal conditions were investigated. Under the optimal conditions, the analytical curve of Fe³⁺ gave a linear dynamic range of 4.0 × 10^?7 mol(L^?1～6.0 × 10^?4 mol(L^?1, with a detection limit of 36 μg/L. When the established CD-RTP method was applied to determine the concentrations of Fe(III) in synthetic samples, the experiment results demonstrated that the range of recovery was 97.3%–102%, with a relative standard deviation less than 2.05% (n = 6).     

Peroxyoxalate Chemiluminescence Based on Fluorescent Conjugated Polymer for the Determination of Triton X-100

A novel peroxyoxalate chemiluminescence system has been designed for the determination of Triton X‐100 (TX‐100), in which a hydrophobic fluorescent conjugated polymer, poly[2,5‐bisnonyloxy‐1,4‐phenylene‐ethynylene‐9,10‐anthrylene] (PPEA) was employed as a fluorophor. A strong enhanced intensity of chemiluminescence (CL) was observed in the presence of TX‐100, due to the improved emission efficiency of PPEA in the presence of TX‐100. Under optimum conditions, the detection range of Triton X‐100 is between 1.0×10^?7 and 1.0× 10^?4 mol·L^?1, with a detection limit at 6.0×10^?8 mol·L^?1. The relative standard deviation is 2.4% (n=6) for 1.0×10^?6 mol·L^?1 Triton X‐100. This method provides satisfying results in the detection of TX‐100 in nature water and biological samples with high sensitivity and wide linear range.     

Ascorbic Acid Induced Enhancement of Room Temperature Phosphorescence of Sodium Tripolyphosphate‐Capped Mn‐Doped ZnS Quantum Dots: Mechanism and Bioprobe Applications

Although quantum dot (QD)‐based room temperature phosphorescence (RTP) probes are promising for practical applications in complex matrixes such as environmental, food and biological samples, current QD‐based‐RTP probes are not only quite limited but also exclusively based on the RTP quenching mechanism. Here we report an ascorbic acid (AA) induced phosphorescence enhancement of sodium tripolyphosphate‐capped Mn‐doped ZnS QDs, and its application for turn‐on RTP detection. The chelating ability allows AA to extract the Mn and Zn from the surface of the QDs and to generate more holes which are subsequently trapped by Mn²⁺, while the reducing property permits AA to reduce Mn³⁺ to Mn²⁺ in the excited state, thereby enhancing the excitation and orange emission of the QDs. The enhanced RTP intensity of the QDs increases linearly with the concentration of AA in the range of 0.05–0.8 μM . Thus, a QD‐based RTP probe for AA is developed. The proposed QD‐based turn‐on RTP probe avoids tedious sample pretreatment, and offers good sensitivity and selectivity for AA in the presence of the main relevant metal ions and other molecules in biological fluids. The limit of detection (3s) of the developed method is 9 nM AA, and the relative standard deviation is 4.8 % for 11 replicate detections of 0.1 μM AA. The developed method is successfully applied to the analysis of real samples of human urine and plasma for AA with quantitative recoveries from 96 to 105 %.     

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.     

Kinetic Spectrophotometric Determination of Thiols and Ascorbic Acid

Abstract

This paper describes a kinetic spectrophotometric method for the determination of L‐ascorbic acid (AA) and thiols (RSH). Absorbance of Fe(II)‐phen complex formed during the reaction of AA or RSH with Fe(III)‐phen was continuously measured at 510 nm by double‐beam spectrophotometer with flow cell. For determination some thiols, the catalytic effect of Cu²⁺ ions was used. AA and RSH can be determined in concentration ranges from 4.0×10^?6 to 4.0×10^?5 M and from 8.0×10^?6 to 8.0×10^?5 M, respectively. The applicability of the proposed method was demonstrated by determination of chosen compounds in pharmaceutical dosage forms.     

Determination of trace glucose and forecast of human diseases by affinity adsorption solid substrate-room temperature phosphorimetry based on triticum vulgaris lectin labeled with dendrimers-porphyrin dual luminescence molecule

In this paper, 3.5-generation polyamidoamine dendrimers (3.5G-D)-porphyrin (P) dual luminescence molecule (3.5G-D-P) was developed as a new phosphorescence-labeling reagent. Meanwhile, the room temperature phosphorescence (RTP) characteristics of 3.5G-D-P and its product of labeling triticum vulgaris lectin (WGA) on the surface of polyamide membrane (PAM) were studied. Results showed that in the presence of heavy atom perturber LiAc, 3.5G-D and P of 3.5G-D-P molecule could emit strong and stable RTP on the PAM. And the Tween-80 would spike thoroughly the phosphorescence signal of 3.5G-D and P; moreover, specific affinity absorption (AA) reaction between the products (Tween-80-3.5G-D-P-WGA) of WGA labeled with Tween-80-3.5G-D-P and glucose (G) was carried out. The products of the AA reaction could keep good RTP characteristics of 3.5G-D and P dual luminescence molecule, and the DeltaI(p) was linear correlation to the content of G. According to the facts above, a new method of affinity adsorption solid substrate-room temperature phosphorimetry (AA-SS-RTP) for the determination of trace G was established, basing on WGA labeled with Tween-80-3.5G-D-P dual luminescence molecule. The detection limit of this method was 0.13fgspot(-1) (1.7x10(-12)moll(-1), 3.5G-D) and 0.14fgspot(-1) (2.2x10(-12)moll(-1), P). Determination of G in human serum using excitation/emission wavelength of either 3.5G-D or P, the result was coincided with enzyme-linked immunosorbent assay (ELISA). Not only the sensitivity and accuracy of this method were higher, but also the flexibility of AA-SS-RTP was obviously improved and the applicability was wider.     

Organic Room‐Temperature Phosphorescence with Strong Circularly Polarized Luminescence Based on Paracyclophanes

Pure organic materials with intrinsic room‐temperature phosphorescence typically rely on heavy atoms or heteroatoms. Two different strategies towards constructing organic room‐temperature phosphorescence (RTP) species based upon the through‐space charge transfer (TSCT) unit of [2.2]paracyclophane (PCP) were demonstrated. Materials with bromine atoms, PCP‐BrCz and PPCP‐BrCz, exhibit RTP lifetime of around 100 ms. Modulating the PCP core with non‐halogen‐containing electron‐withdrawing units, PCP‐TNTCz and PCP‐PyCNCz, successfully elongate the RTP lifetime to 313.59 and 528.00 ms, respectively, the afterglow of which is visible for several seconds under ambient conditions. The PCP‐TNTCz and PCP‐PyCNCz enantiomers display excellent circular polarized luminescence with dissymmetry factors as high as ?1.2×10^?2 in toluene solutions, and decent RTP lifetime of around 300 ms for PCP‐TNTCz enantiomers in crystalline state.     

Spectrophotometric Determination of Human Immunoglobulin G Based on Enlargement of Gold Nanoparticles

Based on the sandwich immunoreaction and enlargement of colloidal gold, a simple spectrophotometric determination of human immunoglobulin G (IgG) was developed. The sandwich immunoreaction among the goat‐anti‐human IgG, the human IgG and goat‐anti‐human IgG labeled with colloidal gold was completed on the surface of 96 well clear polystyrene high bind stripwell(tm) microplate. The immobilized colloidal gold was enlarged by the reaction of 0.01% HAuCl₄ with 0.4 mmol·L^?1 NH₂OH·HCl. A common UV‐Vis spectrophotometer was employed to measure the absorption of the colloidal gold enlarged. The absorption signal of colloidal gold is proportional to the logarithm of human IgG concentration ranging from 5.0×10^?9 to 2.0×10^?5 g·mL^?1, which is comparable with those obtained by other immunoassays. In the proposed method, the immobilized colloidal gold can be easily enlarged and a new absorption band is present at about 620 nm, which makes the signal be recorded with a common medical analyzer. This spectrophotometric determination can be made in a common laboratory without the well‐trained technician and the special equipment.     

Simultaneous Detection of Dopamine and Uric Acid under Coexistence of Ascorbic Acid with DNA/Pt Nanocluster Modified Electrode

A novel biosensor by electrochemically codeposited Pt nanoclusters and DNA film was constructed and applied to detection of dopamine (DA) and uric acid (UA) in the presence of high concentration ascorbic acid (AA). Scanning electron microscopy and X‐ray photoelectron spectroscopy were used for characterization. This electrode was successfully used to resolve the overlapping voltammetric response of DA, UA and AA into three well‐defined peaks with a large anodic peak difference (ΔE_pa) of about 184 mV for DA and 324 mV for UA. The catalytic peak current obtained from differential pulse voltammetry was linearly dependent on the DA concentration from 1.1× 10^?7 to 3.8×10^?5 mol·L^?1 with a detection limit of 3.6×10^?8 mol·L^?1 (S/N=3) and on the UA concentration from 3.0×10^?7 to 5.7×10^?5 mol·L^?1 with a detection limit of 1.0×10^?7 mol·L^?1 with coexistence of 1.0×10^?3 mol·L^?1 AA. The modified electrode shows good sensitivity and selectivity.     

Catalytic Adsorptive Stripping Voltammetry at a Carbon Paste Electrode for the Determination of Amiodarone

Voltammetry using solid electrodes usually suffers from the contamination due to the deposition of the redox products of analytes on the electrode surface. The contamination has resulted in poor reproducibility and overelaborate operation procedures. The use of the chemical catalysis of oxidant on the reduction product of analyte not only can eliminate the contamination of analyte to solid electrodes but also can improve the faradaic response of analyte. This work introduced both the catalysis of oxidant K2S2O8 and the enhancement of surfactant Triton X-100 on the faraday response of amiodarone into an adsorptive stripping voltammetry at a carbon paste electrode for the determination of amiodarone. The method exhibits high sensitivity, good reproducibility and simple operation procedure. In 0.2 mol·L^-1 HOAc-NaOAc buffer （pH=5.3） containing 2.2×10^-2 mol·L^-1 K2S2O8 and 0.002% Triton X-100, the 2.5th-order derivative stripping peak current of the catalytic wave at 0.3 V （vs. Ag/AgCl） is rectilinear to amiodarone concentration in the range of 2.0×10^-10-2.3×10^-8 mol·L^-1 with a detection limit of 1.5×10^-10 mol·L^-1 after accumulation at 0 V for 30 s.     

Electrocatalytic Oxidation and Determination of Dopamine in the Presence of Ascorbic Acid and Uric Acid at a Poly (4‐(2‐Pyridylazo)‐Resorcinol) Modified Glassy Carbon Electrode

A sensitive and selective electrochemical method for the determination of dopamine (DA) was developed using a 4‐(2‐Pyridylazo)‐Resorcinol (PAR) polymer film modified glassy carbon electrode (GCE). The PAR polymer film modified electrode shows excellent electrocatalytic activity toward the oxidation of DA in a phosphate buffer solution (PBS) (pH 4.0). The linear range of 5.0×10^?6–3.0×10^?5 M and detection limit of 2.0×10^?7 M were observed. Simultaneous detection of AA, DA and UA has also been demonstrated on the modified electrode. This work provides a simple and easy approach to selective detection of DA in the presence of AA and UA.     

Room Temperature Phosphorescence of 1-Bromo-4-(bromoacetyl)naphthalene Induced by Sodium Deoxycholate

Sodium deoxycholate (NaDOC) can induce 1-bromo-4-(bromoacetyl)naphthalene (BBAN) to undergo strong room temperature phosphorescence (RTP) without the removal of dissolved oxygen from the solution. RTP spectra, phosphorescence polarization and ¹³C NMR results, along with the molecular modeling calculations, supported the conclusion that BBAN molecule was combined in a sandwich with two NaDOC molecules by a “back-to-back” hydrophobic interaction arising from the apolar faces of the NaDOC molecules, which provided BBAN with a rigid enough microenvironment to produce RTP.