Label-free and ultrasensitive fluorescence detection of cocaine based on a strategy that utilizes DNA-templated silver nanoclusters and the nicking endonuclease-assisted signal amplification method

Abstract

A general and reliable strategy for the detection of cocaine was proposed utilizing DNA-templated silver nanoclusters as signal indicators and the nicking endonuclease-assisted signal amplification method. This strategy can detect cocaine specifically with a detection limit as low as 2 nM by using a small volume of 5 μL.

Chromogenic and Fluorogenic Probes for the Detection of Illicit Drugs

“…Silver nanoclusters (AgNCs) can be used as an indicator for cocaine detection in the presence of DNA templates utilizing the advantages of the nicking endonuclease‐assisted signaling amplification (NEASA) strategy (Figure ) . The reported aptasensor consists of three different DNA sequences, DNA1, DNA2, and DNA3.…”

Lable-free quadruple signal amplification strategy for sensitive electrochemical p53 gene biosensing

“…So far, various smart nuclease including restriction endonucleases Zhu et al, 2014) and exonucleases (Wang et al, 2014;Liu et al, 2013aLiu et al, , 2013b have been applied for bioanalytical applications. Among them, the nicking endonuclease signal amplification (NESA) as a newly developed technique attracted researchers' attention to design sensitive biosensors of target DNA for their autonomous circular amplification and simple operations (Miao et al, 2013;Zhang et al, 2014b). As one of the nicking endonuclease, N.BstNB I enzyme cleaves only one strand of a double stranded DNA four bases away from the 3'-end of its recognition sequence (5′-GAGTC-3′), which have been used extensively (Zhou et al, 2013).…”

DNA-scaffolded silver nanoclusters as an on–off label-free fluorescence probe for the selective detection of endonuclease activity and inhibition

“…13 Various fluorescent assays have been developed to detect endonucleases later, for example, Huang group used quantum dots (QDs) as fluorophore and made used of different kinds of quenchers to realize multiplexed detection of endonuclease based on fluorescence resonance energy transfer (FRET), 12 they also utilized gold nanoparticle as quencher and volume enhancement factor for detecting endonucleases. 31,34 They made use of DNA-AgNCs as label-free fluorescent probe to detect many types of materials, for examples, the Qian group took advantage of DNA-AgNCs as fluorescent probe for detection of endonuclease activity and inhibition; 17 the Peng group also determine micrococcal nucleaseions by DNA-AgNCs; 31 The Ye group used DNA-AgNCs as probe to monitor specific DNA; 35 the Zhang group utilized DNA-AgNCs as the signal response of fluorescent molecule to detect cocaine; 36 the Willner group realized multiplexed analysis of genes by using DNA-AgNCs. 16 Noble metal nanoclusters (NCs) have attracted great research interests around the field of bio-analytic chemistry, because they exhibit excellent properties, such as facile synthesis, tunable fluorescence emission (ranging from visible to near-IR), ultrafine size, low toxicity, good photostability and biocompatibility.…”