Acetylcholinesterase Immobilized on Magnetic Mesoporous Silica Nanoparticles Coupled with Fluorescence Analysis for Rapid Detection of Carbamate Pesticides

Abstract

Herein, we successfully synthesized a magnetic mesoporous material, Fe 3 O 4 @SiO 2 @mSiO 2 , and acetylcholinesterase (AChE) was immobilized by a covalent bonding method. The tolerance ability of immobilized AChE (by magnetic mesoporous silica nanoparticles) in different organic solvents was better than that of free AChE. Furthermore, the magnetic character of the fixed AChE improved the detection sensitivity and reliability for carbofuran, methomyl, isoprocarb, and carbaryl. The limit of detection (LOD) of carbofuran, methomyl, isoprocarb, and carbaryl was 0.01, 0.22, 0.26, and 0.43 μM, respectively. It shows a good correlation between carbamate pesticides (CMs) and the inhibition rate of Fe 3 O 4 @SiO 2 @mSiO 2 -AChE in a given concentration range. The linear ranges of carbofuran, methomyl, isoprocarb, and carbaryl were 0.02−0.90, 0.31−12.33, 0.27−5.17, and 0.50−14.91 μM, respectively. Chinese cabbage and cucumber spiked with four CMs were used as field-incurred samples to prove the feasibility of the developed method. According to the maximum residue limits, the results were satisfactory, with recovery rates between 77.03 and 110.07%, and the RSDs ranged from 3.17 to 6.79%. The stability of immobilized AChE in organic solvents was improved with enhanced sensitivity for detecting pesticide residues.

A Butyrylcholinesterase Camera Biosensor Tested for Carbofuran and Paraoxon Assay

“…It is suitable for a contemporary processing of up to 121 samples with the final result of the assay in approximately 70 minutes. The biosensor does not bring significant improvement to the other known types biosensors for inhibitors of cholinesterase assay like electrochemical [ 29 – 31 ] and optical [ 32 , 33 ] one regarding to sensitivity or achieved limits of detection. However, here presented biosensor offers better feasibility and applicability in harsh conditions.…”

Highly Sensitive and Rapid Screening Technique for the Detection of Organophosphate Pesticides and Copper Compounds Using Bifunctional Recombinant TrxA-PvCarE1

“…OPs were analyzed using a modified version of the method described elsewhere. 22 The sample solution was dried to near dryness under nitrogen and then redissolved in 0.5 mL of 40 mM PBS (pH 7.5).…”

Nanomaterial-Based Fluorescent Biosensor for Food Safety Analysis

“…Magnetic mesoporous particles are composed of silica spheres. Zhu et al immobilized acetylcholinesterase (AChE) on the surface of Fe 3 O 4 @SiO 2 @mSiO 2 via covalent bonds [ 79 ]. They act as fluorescence tracers for carbamate pesticide detection in Chinese cabbage and cucumber plants.…”