Preparation of molecularly imprinted polymer coated quantum dots to detect nicosulfuron in water samples

Abstract

A novel dual-function material was synthesized by anchoring a molecularly imprinted polymer (MIP) layer on Mn-doped ZnS quantum dots (QDs) via a sol-gel process using 3-aminopropyltriethoxysilane (APTES) as a functional monomer, tetraethoxysilane (TEOS) as cross-linker, and nicosulfuron as template through a surface imprinting method. The amino groups in the APTES interact with the functional groups in the template molecules to form a complex through hydrogen bonding. The energy of the QDs was transferred to the complex, resulting in the quenching of the QDs and thus decreasing the fluorescence intensity, which allowed the nicosulfuron to be sensed optically. Fluorescence intensity from MIP-coated QDs was more strongly quenched by nicosulfuron than that of the non-imprinted polymer, which indicated that the MIP-coated QDs which acted as a fluorescence probe could selectively recognize nicosulfuron. Under the optimal conditions, it can detect down to 1.1 nmol L(-1) of nicosulfuron, and a linear relationship has been obtained covering the concentration range of 12-6000 nmol L(-1). The recoveries were in the range from 89.6 to 96.5 %, and the relative standard deviations were in the range of 2.5-5.7 %. The present study established a new strategy to combine inorganic (Mn-doped ZnS QDs)-organic MIPs, which is successfully applied to determine nicosulfuron in water samples.

A nanocomposite optosensor containing carboxylic functionalized multiwall carbon nanotubes and quantum dots incorporated into a molecularly imprinted polymer for highly selective and sensitive detection of ciprofloxacin

“…The pH level had significant effects on fluorescence quenching of QDs due to their sensitivity to the surrounding environment such as acids, bases, metal ions and organic molecules [18,43]. In this work, the effect of pH between 6.0to 9.0 on the determination of ciprofloxacin was investigated.…”

Ultrasensitive detection of glibenclamide based on its enhancing effect on the fluorescence emission of CdTe quantum dots

“…In recent decades, luminescent quantum dots (QDs) have been found attractive in the analytical field for the detection aims based on the quenching or the enhancement effect of the analytes on the fluorescence emission of QDs . QDs have exceptional properties such as high photostability, greater quantum efficiency, wide absorption and narrow emission spectra, large Stokes shift, surface functionality and large surface‐to‐volume ratio, which have made them superior to the usual organic fluorescent compounds .…”

<p>Toxicity and serum metabolomics investigation of Mn-doped ZnS quantum dots in mice</p>

“…ZnS quantum dots (QDs) are IIB–VIA semiconductors and are considered to be good hosts when doped with Mn (3D transition metal ions) 1. Depending on their special luminescence property, Mn-doped ZnS QDs have been used for the detection of various substances by different surface modifications, including metal ions [copper(II), Fe(II), manganese(VII), and Pb(II)],2–5 environmental hazards (halobenzoquinones, patulin, florfenicol, and nicosulfuron),6–9 cocaine and its metabolites,10–12 drugs (atropine),13 biological molecules (thrombin,14 serotonin/5-hydroxytryptamine,15 dopamine,16 xanthine oxidase,17 prostate-specific antigen,18 glycoproteins19 and DNA20), and cancer cells 21. The widespread use of Mn-doped ZnS QDs has raised many toxicological concerns.…”