CdTe‐paper‐based Visual Sensor for Detecting Methyl Viologen

Abstract

This study developed a method on detecting methyl viologen (paraquat) using a CdTe-paper-based visual sensor. The CdTe Qdots were immobilized on the paper using glycerin. The volume percentages of CdTe in glycerin were optimized to be 50%. The sensing principle is that the methyl viologen quenches the fluorescence intensity of CdTe Qdots in a concentration dependent manner. The sensor is linearly response to the logarithm concentration of the methyl viologen in the range from 0.39 μmol/L to 3.89 mmol/L with a detection limit of 0.16 μmol/L and the correlation coefficient R 2 of 0.99. Three parallel experiments at the methyl viologen concentration of 38.89 μmol/L give a relative error of 2.45%, which indicates a good reproducibility. The sensor is not disturbed by other pestisides including omethoate, anilofos, machete and glyphosate isopropylamine salt. The advantages of this sensor are disposable, stable, convenient, and easy to operate.

A Photo‐Responsive Charge‐Assisted Hydrogen‐Bonded Organic Network with Ultra‐Stable Viologen Radicals

“…Due to the electron‐deficient character and the low‐energy LUMO of viologen derivatives, [ 27‐30 ] viologen‐based materials usually undergo photoinduced electron transfer (PET) from electron‐ rich units to electron‐deficient units, accompanied by the obvious…”

Advances in Microfluidic Paper-Based Analytical Devices for Food and Water Analysis

“…The only paper-based approach applied to herbicide detection that has utilized FL as a method of detection for methyl viologen is presented by Su et al [ 67 ]. The method was based on the integration of CdTe Qdots on the paper device and the CdTe quenching effect in the presence of the target methyl viologen.…”

Utilization of Red‐Light‐Emitting CdTe Nanoparticles for the Trace‐Level Detection of Harmful Herbicides in Adulterated Food and Agricultural Crops

“…[12][13][14][15][16][17][18][19] In some cases,n egatively chargedp olymers or nanoparticles have also been used for the detection of PQ through electrostatic interactions. [20][21] However, the poor selectivity of these probes for PQ over other compounds often limits their ability to analyze PQ concentrationsi nc omplex real-lifes amples. Moreover,t od ate, there are no reports on the successful discrimination of PQ from its structurally relateda nalogue, diquat (DQ).…”

“…The colorimetric probes reported so far for paraquat (PQ) have mainly exploited host–guest interactions of macrocycles such as cucurbit[8]uril, pillar[5]arene, or carboxylato‐biphen[3]arene as host molecules . In some cases, negatively charged polymers or nanoparticles have also been used for the detection of PQ through electrostatic interactions . However, the poor selectivity of these probes for PQ over other compounds often limits their ability to analyze PQ concentrations in complex real‐life samples.…”