Poly(thymine)-templated fluorescent copper nanoparticles for label-free detection of N-acetylcysteine in pharmaceutical samples

Abstract

26In this paper, a novel and label-free fluorescent sensing strategy has been 27 developed for thiol-containing drugs detection by using poly(thymine) (poly 28 T)-templated copper nanoparticles (Cu NPs) as fluorescent probes. N-acetylcysteine 29 (NAC), one of thiol-containing drugs, was selected as a model case in this strategy. 30 The fluorescence intensity of poly T-templated Cu NPs was found to be quenched 31 effectively with the increasing concentration of NAC, due to the formation of a 32 coordination complex by the Cu-S metal-ligand bond between the NAC and poly 33 T-tempaled Cu NPs. However, the fluorescence intensity was not nearly changed in 34 the presence of other analytes at a 10-fold higher concentration. Under the optimized 35 conditions, the label-free fluorescent sensor achieved highly sensitive and selective 36 detection of NAC with a linear range from 0.2 µM to 100 µM and a detection limit of 37 50 nM. Furthermore, the method was successfully applied in the detection of NAC in 38 pharmaceutical samples. The strategy was free of any fluorescence dye label or 39 complex DNA sequence design, and all the process were performed within 20 minutes 40 at room temperature. Therefore, it could offer a simple, cost-effective, selective and 41 label-free sensing platform for fluorescent detection of thiol-containing drugs in 42 clinical diagnostics. 43 44

Strategies for the Development of Metallic‐Nanoparticle‐Based Label‐Free Biosensors and Their Biomedical Applications

“…Despite various methods that are proposed for the investigation and quantification of thiol‐containing drugs, a simple, less time‐consuming, and cost‐effective method is required. In this effort, Wang and co‐workers reported the identification of NAC (a thiol‐containing drug) by using polythymine‐templated (polyT‐templated) CuNPs as reporter molecules . The fluorescence intensity of polyT‐templated CuNPs was quenched up to 81.6 % in the presence of 100 μ m NAC within 5 min, but there was no change in fluorescence in the absence of NAC.…”

“…In this effort, Wang and co-workersr eported the identification of NAC (a thiol-containing drug) by using polythymine-templated (polyT-templated) CuNPs as reporter molecules. [81] The fluorescencei ntensity of polyT-templated CuNPs was quenched up to 81.6 %i nt he presence of 100 mm NAC within 5min, but there was no change in fluorescencei n the absence of NAC. The hypothetical mechanism behind fluorescenceq uenching was elucidated by the idea that CuNPs in polyT-template formed ac omplex with the thiol group present in NAC.…”

H2O2-mediated fluorescence quenching of double-stranded DNA templated copper nanoparticles for label-free and sensitive detection of glucose

“…This was because the thiol group of GSH and Cys could also quench the uorescence intensity of Cu NPs. 18,36 Thus, a masking agent (N-ethylmaleimide, NEM) was introduced into the sensor system to eliminate interference from GSH and Cys. 34 Aer incubation of GSH or Cys with NEM, a negligible uorescence response was observed, whereas glucose detection was unaffected by the introduction of NEM.…”

An impedimetric determination of alkaline phosphatase activity based on the oxidation reaction mediated by Cu2+ bound to poly-thymine DNA

“…Recently, Qing et al described an ascorbic acid-catalyzed reduction of Cu 2+ entrapped within poly-thymine DNA probe for the formation of uorescence copper nanoparticle (CuNP), which has been used for development of various bioassays. [31][32][33][34][35][36][37][38] Taking this unique feature, Ocaña et al developed an impedimetric method for sensing Cu 2+ . 39 In this method, the rate of ascorbic acid oxidation was signicantly enhanced by DNAtemplated Cu 2+ on the electrode, 40,41 and consequently the electrode surface was covered with oxidation products, resulting in an increase in the electron transfer resistance (R et ) of the electrode.…”