Design and fabrication of electrochemical sensor based on molecularly imprinted polymer loaded onto silver nanoparticles for the detection of 17‐β‐estradiol

Abstract

In this research report, we prepared an electrochemical sensor based on the molecularly imprinted poly(p‐aminophenol) supported by silver nanoparticles capped with 2‐mercaptobenzoxazole for the selective and sensitive detection of endocrine disrupting 17‐β‐estradiol (E2). The electropolymerization of the functional monomer prepared the proposed molecularly imprinted polymer (MIP) composite‐based sensor in the presence of E2 as a template. The recognition materials were characterized using Fourier transform infrared, cyclic voltammetry (CV), square wave voltammetry (SWV), scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and X‐ray powder diffraction techniques. The electrochemical measurements were performed by employing both CV and SWV methods. We did the optimization of critical parameters affecting the sensor performances through the experimental design and verification. The developed sensor showed a linear range from 10 pM to 100 nM with the calculated quantification and detection limits of 1.86 and 6.19 pM, respectively. The incorporation of AgNP with high electrical conductivity into the MIP matrix enhanced the sensor's performance. Furthermore, the sensor was applied to determine E2 in real water samples without any sample preconcentration steps to achieve the percent recovery of 91.87% to 98.36% and acceptable reusability and storage stability performances.

The Role of Silver Nanoparticles in Electrochemical Sensors for Aquatic Environmental Analysis

“…Nevertheless, even strong reducing agents can render AgNPs of various morphologies (quasi-spherical, cubic, twinned structure, and triangles) and larger size distributions when deposited on highly wrinkled and folded graphene nanosheets [ 155 ], or when the Ag(I) precursor is previously encapsulated with a massive chelating ligand [ 156 ], while a precisely controlled green approach can produce remarkably small particles ( d = 5 nm) with high catalytic efficiency [ 168 ]. AgNPs of precise size and shape can also be formed and fine-tuned using electric current [ 79 , 80 , 119 , 182 ]. In electrochemical sensors based on electrodeposited silver nanomaterial [ 81 , 148 ], the addition of silver material was found to play a key role in the trace-level quantification of both trivalent and hexavalent chromium through formation and stabilization of functional bimetallic silver–gold metal oxides [ 81 ], and in the formation of dual-region WE for simultaneous detection of inorganic nitrogen-containing species (nitrate/ammonia) through a signal current channel [ 148 ].…”

“…Aggravation or enhancement of the electron transfer pathway of AgNPs-modified WE leads to the amplification or decrement of voltammetric performance. Two voltammetric platforms based on MIPs supported by AgNPs-decorated GCE have been developed for highly selective and sensitive detection of natural estrogen in environmental and drinking water with picomolar and femtomolar detection limits [ 182 , 183 ]. The detection of the analyte is catalyzed by the AgNPs (signal amplification or inhibition), while the analyte capture and selective recognition were performed by the MIPs.…”

“…The detection of the analyte is catalyzed by the AgNPs (signal amplification or inhibition), while the analyte capture and selective recognition were performed by the MIPs. In the presence of E2, more imprinted cavities of the poly( p -aminophenol) (MIP-pAPh) were occupied, resulting in direct amplification of the current response by AgNPs signal amplification [ 182 ]. The reverse sensing mechanism was proposed for the AgNP/GO/MIP (poly-imidazole; PImi) functional platform [ 183 ].…”

“…This simple sensing platform was remarkably stable (91% of initial current response obtained after 21 days) and applicable in real water matrices with recoveries between 95% and 104%. A voltammetric sensor based on molecularly imprinted polymer (MIP) and 2-mercaptobenzoxazole (2-MBO)-capped AgNP composite material was presented as a novel sensing platform for the highly sensitive and selective determination of E2 in real water samples [ 182 ]. First, the GCE was modified with nanosilver (electrodeposition from 0.5 mM AgNO 3 with addition of a capping agent in 0.1 M PBS under the potential range of −0.7 V to 1.4 V for 7 cycles).…”

Advances in electrochemical sensors based on nanomaterials for the detection of lipid hormone

“…In addition to MIP electrochemical sensors based on carbon nanomaterials, Regasa and Nyokong created an electrochemical sensor based on MIP supported by AgNPs capped with 2-mercaptobenzoxazole (Regasa and Nyokong, 2022). The sensor was used to measure 17β-estradiol in actual water samples without the need of sample preconcentration processes, resulting in satisfactory selectivity, sensitivity, reusability and storage stability performances.…”