A Microfluidic Colorimetric Biosensor for Chlorpyrifos Determination based on Peroxidase-like CuFe2O4/GQDs Magnetic Nanoparticles

Abstract

High-precision and miniature biosensors are in urgent demand with respect to the organophosphorus pesticides used extensively in agriculture, especially for Chlorpyrifos. In this study, the novel CuFe 2 O 4 -Graphene Quantum Dots (CuFe 2 O 4 / GQDs) Magnetic Nano-Particles (MNPs) was prepared to amplify color signal as peroxidase mimetic using one-step hydrothermal method with electrostatic adsorption. Further combined with well-designed microfluidic chip containing enzyme inhibition reaction, color reaction and uV spectrophotometric detection areas, a colorimetric biosensor was developed based on CuFe 2 O 4 /GQDs for Chlorpyrifos determination. Experimental results of the biosensor displayed a linear range from 3.2 × 10 -8 M to 6 × 10 -7 M with a correlation coefficient of 0.99258 under the optimized conditions, and the Limit of Detection (LOD) of 1.07 × 10 -8 M based on S/N = 3 and the sensitivity of 855.26 (absorbance) per 1 mM. Great advantages have been exhibted in the Microfluidic colorimetric biosensor due to the small volume, and high precision for determination of low concentrations of organophosphorus pesticides, largely simplifying the tedious operation and lowing LOD, which is great benefit to the further development of low-cost, portable and high-precision biosensors.

Precisely Navigated Biobot Swarms of Bacteria Magnetospirillum magneticum for Water Decontamination

“…The statics of AMB-1 biobots was demonstrated under the same method except for the magnetic field. After the chlorpyrifos removal process, dynamic groups were centrifuged at 5939 RCF for 10 min, and all groups were quantified by UV–vis spectroscopy, referring to other previous studies. − The different concentrations of chlorpyrifos have also been measured by UV–vis spectroscopy (Figure S6). The removal efficiency of chlorpyrifos (%) was calculated using eq normalR normale normalm normalo normalv normala normall .25em normale normalf normalf normali normalc normali normale normaln normalc normaly .25em ( % ) = C normali − C normalt C normali × 100 where C i is the initial concentration of chlorpyrifos in solution and C t is the final concentration of chlorpyrifos solution after removal.…”

A novel sensing layer based on metal–organic framework UiO-66 modified with TiO2–graphene oxide: application to rapid, sensitive and simultaneous determination of paraoxon and chlorpyrifos

“…Of this subject, enzymatic biosensors and immunosensors are commonly employed for the determination of POX and CPF. [10][11][12][13][14][15][16] Although enzyme-based sensors in most cases exhibit excellent performance for detection of organophosphorus insecticides, there are still serious problems and limitations regarding their fabrication, storage, and stability while nonenzyme sensors are not associated with these limitations.…”

Construction of a novel electrochemical sensor based on molecularly imprinted polymers for the selective determination of chlorpyrifos in real samples

“…Electrochemical methods have attracted considerable attention because of their higher sensitivity, lower cost, and faster operation compared to the other methods . In the literatures, many sensors have been prepared for the direct electrochemical determination of CPF, such as Ag/Cu alloy nanoparticles and a graphene nanocomposite paste electrode , an electrochemical immune sensor , an electrochemical biosensor , and an impedimetric sensor . Generally, the direct electrochemical methods exhibited high sensitivity, but their selectivity, stability, and repeatability were not satisfactory.…”