Integrated optical and electrochemical detection of Cu²⁺ ions in water using a sandwich amino acid–gold nanoparticle-based nano-biosensor consisting of a transparent-conductive platform

Abstract

The transparent-conductive platforms of ITO/GNPs/l-cys⋯Cu2+⋯l-cys/GNPs were fabricated for quantitation of Cu2+ ions in water samples using combined LSPR and SWV methods.

An overview of Structured Biosensors for Metal Ions Determination

“…Additional platforms used for the construction of biosensors include indium tin oxide glass (ITO) electrodes and field-effect transistors (FET). The former, known for its high conductivity and transparency, was employed for the determination of Cu(II) in tap water [92] after the electrodeposition of GNP modified with amino acids. Modifications of FET sensors were carried out at the SiO 2 gate of the device and used for Cd(II) [129], Cu(II) [39], Fe(III) [30], and Ca(II) [84,125] determinations in biological fluids and drinks.…”

“…Nanomaterials have unambiguously set their place in many areas. They have been employed both as a recognition and support agent in biosensing detection due to their chemical, physical, electrical, and optical properties compared to bulk materials [92]. Furthermore, the modification of sensors with nanoparticles, especially electrodes, yielded higher stability, sensitivity, and repeatability [30].…”

“…The response of the determination of Hg(II) increased up to 60% with a GNP-coated electrode compared to a bare GE [135]. The electrochemical and adsorptive coatings of GCE [98,124,133,139,158,159,167,175], SPCE [96], paper [59,76], and glass [28,92,131] sensors with GNP allowed for the immobilization of compounds via thiol bonding and higher conductivity to achieve low detection limits. The deposition of reduced graphene oxide was generally used to modify carbon-based sensors before the deposition of GNP to enhance the sensitivity due to the synergistic effect of these materials [40,135].…”

Highly Sensitive and Selective Copper (II)-Catalyzed Dual-DNAzyme Colorimetric Biosensor Based on Exonuclease III-Mediated Cyclical Assembly

“…Traditional analytical techniques for sensing Cu 2+ depend upon expensive analytical equipment [3,4], but the onsite rapid detection of these methods is limited due to their complex sample pretreatments and high operating cost. Recently, biosensor methods that have shown good sensitivity and selectivity have been widely used in the rapid detection of Cu 2+ , such as fluorescent biosensors [5,6], plasmonic biosensors [7,8], colorimetric biosensors [9,10], and electrochemical biosensors [11][12][13]. By comparing the aforementioned biosensors, Cu 2+ -cleaving DNAzyme (Cu-DNAzyme) is the signal recognition and transition of choice, nucleic acid amplification is the best method to increase sensitivity, and colorimetric analysis is the most convenient option.…”

A Simple Strategy for Easily Assembling 3D Printed Miniaturized Cells Suitable for Simultaneous Electrochemical and Spectrophotometric Analyses

“…The hyphenation of electrochemical methods and optical spectroscopy is expected to be a challenging idea to enhance the information which can be gained on complex chemical systems [45][46][47][48][49]. Moreover, the simultaneous availability of electrochemical and spectrophotometric data can make possible their mutual control, thus providing the autovalidation of the results collected [50][51][52].…”