In this paper, the design of a novel sandwich-type electrochemical aptasensor was reported for an ultrasensitive mercury ion (Hg2+) detection in water samples, which labeled with two-labeled aptamer (Apt) sequences. The used Apts were Apt1 and Apt2 as the capture and signal probe, respectively. The Apt1 probe was immobilized on the poly(4-aminobenzoic acid) (p-ABA) and quantum dots (QDs) film as the platform, as well as the Apt2 reporter was labeled with ferrocene. In the presence of Hg2+, the strong coordination complex has been formed between the specific thymine of the Apt1, Hg2+, as well as the thymine of the Apt as T–Hg2+–T adduct. The QDs and p-ABA were applied for increasing the conductivity of platform and suitable binding of the recognition elements. Under the optimized conditions, the constructed aptasensor illustrated either a wide linear relationship between the logarithm of Hg2+ concentration and current, from 0.05 to 100 nM and also an excellent low limit of detection of 0.01 nM. The quality of carefully choosing, an excellent stability and specificity sensitivity of the designed aptasensor, was investigated by spiked tap water samples as real sample. Moreover, the aptasensor exhibits the good reproducibility as well as has high selectivity for the other cations. The recoveries of the Hg2+ assay of the tap water samples were acquired satisfactorily which imply the generated aptasensor can use Hg2+ measurement in the real laboratories.
In present paper, the potential of B21N21 and Al21P21 nanocages as anode electrodes of Li-ion, Na-ion and K-ion batteries by using of density functional theory was investigated. The effects of adoption of B21N21 and Al21P21 nanocages with halogen atoms on potential of metal-ion batteries were examined. Results showed that Al21P21 as anode electrode in metal ion batteries has higher potential than B21N21. Results indicated that K-ion battery has higher cell voltage than Li-ion and Na-ion batteries. Results showed that adoption of B21N21 and Al21P21 with halogen atoms increased the cell voltage of metal-ion batteries. Results showed that F-doped metal-ion batteries have higher cell voltage than Cl- and Br-doped metal-ion batteries. It can be concluded that F–Al20P21 as anode electrode in metal-ion battery has higher potential than F–B20N21. 相似文献
A new magnetic oxidation catalyst was prepared using immobilization of tungstophosphoric acid on poly(N-vinylimidazole) entrapped magnetic nanozeolite and characterized by FTIR, TGA, XRD, SEM, TEM, EDX, VSM, and ICP-OES. The resulting heterogeneous catalyst displays high catalytic performance for selective oxidation of alcohols compared to the other catalysts. The catalyst could be reused eight times without any loss of catalytic activity. 相似文献
Summary. Alkyl isocyanides react with dialkyl acetylendicarboxylates in the presence of CH-acids such as cyclopentane-1,3-dione, cyclohexane-1,3-dione, or 5,5-dimethylcyclohexane-1,3-dione to afford highly functionalized 4H-pyrans in fairly high yields. In the case of reaction between dimethyl acetylenedicarboxylate and 5,5-dimethylcyclohexane-1,3-dione in the presence of cyclohexyl isocyanide or benzyl isocyanide tetrahydro-cyclopenta[b]pyran derivatives were isolated in addition to the 4H-pyran system. The free energy barrier (96.9kJmol–1) for restricted rotation around the polarized double bond of the enaminone moiety in dimethyl 2-[cyclohexylamino-(4,4-dimethyl-2,6-dioxocyclohexylidene)methyl]but-2-enedioate was determined by dynamic NMR spectroscopy. 相似文献
Microchimica Acta - The authors describe the preparation of two kinds of metal-organic frameworks (MOFs), referred to as TMU-8 and TMU-9. The MOFs were applied to the preconcentration of the ions... 相似文献
In this work, the natural nanozeolite clinoptilolite (Nano CP) was successfully functionalized by propylsulfonic acid and applied as efficient heterogeneous catalyst for the synthesis of quinoxaline derivatives in aqueous media. The nanocatalyst was characterized by various techniques such as CHN, XRD, FT-IR, BET, TGA/DTA, SEM, TEM and TEM-EDS. The results show its applicability as green, reusable and promising catalyst in organic synthesis. It was found that the nanocatalysts could be recycled and reused eight times without significant loss of catalytic activities. 相似文献
In this study, a simple and rapid extraction method based on the application of polypyrrole‐coated Fe3O4 nanoparticles as a magnetic solid‐phase extraction sorbent was successfully developed for the extraction and preconcentration of trace amounts of formaldehyde after derivatization with 2,4‐dinitrophenylhydrazine. The analyses were performed by high‐performance liquid chromatography followed by UV detection. Several variables affecting the extraction efficiency of the formaldehyde, i.e., sample pH, amount of sorbent, salt concentration, extraction time and desorption conditions were investigated and optimized. The best working conditions were as follows: sample pH, 5; amount of sorbent, 40 mg; NaCl concentration, 20% w/v; sample volume, 20 mL; extraction time, 12 min; and 100 μL of methanol for desorption of the formaldehyde within 3 min. Under the optimal conditions, the performance of the proposed method was studied in terms of linear dynamic range (10–500 μg/L), correlation coefficient (R2 ≥ 0.998), precision (RSD% ≤ 5.5) and limit of detection (4 μg/L). Finally, the developed method was successfully applied for extraction and determination of formaldehyde in tap, rain and tomato water samples, and satisfactory results were obtained. 相似文献
Chemistry of Heterocyclic Compounds - The microreview considers recent methodologies for the synthesis of 2H-thiochromenes including enantioselective synthesis, multistep synthesis,... 相似文献
A simple, new two-step procedure for the synthesis of novel tricyclic pyrrolo[2,1-a]isoquinoline derivatives is described. The initially prepared polysubstituted pyrroles obtained via the four-component condensation of arylglyoxals, cyclic 1,3-dicarbonyls, aminoacetaldehyde dimethyl acetal, and β-keto esters subsequently underwent intramolecular acid-catalyzed cyclization to the desired products in moderate to good yields. 相似文献