Gold Nano/Micro-Islands Overcome the Molecularly Imprinted Polymer Limitations to Achieve Ultrasensitive Protein Detection

Abstract

Here, we report on an electrochemical biosensor based on core–shell structure of gold nano/micro-islands (NMIs) and electropolymerized imprinted ortho-phenylenediamine (o-PD) for detection of heart-fatty acid binding protein (H-FABP). The shape and distribution of NMIs (the core) were tuned by controlled electrodeposition of gold on a thin layer of electrochemically reduced graphene oxide (ERGO). NMIs feature a large active surface area to achieve a low detection limit (2.29 fg mL–1, a sensitivity of 1.34 × 1013 μA mM–1) and a wide linear range of detection (1 fg mL–1 to 100 ng mL–1) in PBS. Facile template H-FABP removal from the layer (the shell) in less than 1 min, high specificity against interference from myoglobin and troponin T, great stability at ambient temperature, and rapidity in detection of H-FABP (approximately 30 s) are other advantages of this biomimetic biosensor. The electrochemical measurements in human serum, human plasma, and bovine serum showed acceptable recovery (between 91.1 ± 1.7 and 112.9 ± 2.1%) in comparison with the ELISA method. Moreover, the performance of the biosensor in clinical serum showed lower detection time and limit of detection against lateral flow assay (LFA) rapid test kits, as a reference method. Ultimately, the proposed biosensor based on the core–shell structure of gold NMIs and MIP opens interesting avenues in the detection of proteins with low cost, high sensitivity and significantstability for clinical applications.

Electroanalytical point-of-care detection of gold standard and emerging cardiac biomarkers for stratification and monitoring in intensive care medicine - a review

“…Last, as noted above, the detection of H-FABP is limited and generally based upon immunoassays, with very limited reports using MIPs [ 208 ]. For example, Sanati et al [ 208 ] reported the development of a MIP based biosensor, based upon ITO modified electrochemically reduced graphene oxide (ERGO).…”

“…Last, as noted above, the detection of H-FABP is limited and generally based upon immunoassays, with very limited reports using MIPs [ 208 ]. For example, Sanati et al [ 208 ] reported the development of a MIP based biosensor, based upon ITO modified electrochemically reduced graphene oxide (ERGO). These were modified with highly active surface area core–shelled gold nano/micro-islands (NMIs) via electrodeposition, which allows their size to be tuneable via controlling the electrodeposition process.…”

“…The MIPs were fabricated via the electropolymerisation of ortho -phenylenediamine using CV in the presence of the target H-FABP. The MIP biosensor mechanism proceeds via a “signal off” and using DPV, exhibited a linear range from 1 fg mL –1 to 100 ng mL –1 towards H-FABP with a LOD of 2.29 fg mL –1 which was attributed to the high surface area of the NMIs and ERGO [ 208 ]. The sensor demonstrated two key aspect of MIPs that makes them attractive as the basis of electrochemical sensors, namely, stability and selectivity.…”

Application progress of magnetic molecularly imprinted polymers chemical sensors in the detection of biomarkers

“…130 At present, the detection of H-FABP is mostly focused on combining antibody capture probe and nanomaterials, while the research of MIPs-ECS is less. 131,132 Sanati et al 133 developed an electrochemical biosensor with a core–shell structure of nano/micro-islands (NMIS) and MIPs prepared by electrodeposition method to detect H-FABP in biological fluids. The steps of the MIPs biosensor fabrication and H-FABP detection are shown in Fig.…”

Optical cytosensors for the detection of circulating tumour cells

“…The selection of appropriate biorecognition elements significantly affects the overall analytical cost and lifetime performance of biosensors. 21,22 Biorecognition elements, including antibodies, DNA-aptamers, recognition peptides and some synthetic molecules, have been employed to detect cancer cells using cytosensors. These biorecognition elements exhibit a high affinity to antigens on the cancer cells' surface, thereby making specific bonding with cancer cells.…”