Recent Advances in Bimetallic Nanoporous Gold Electrodes for Electrochemical Sensing

Bimetallic nanocomposites and nanoparticles have received tremendous interest recently because they often exhibit better properties than single-component materials. Improved electron transfer rates and the synergistic interactions between individual metals are two of the most beneficial attributes of these materials. In this review, we focus on bimetallic nanoporous gold (NPG) because of its importance in the field of electrochemical sensing coupled with the ease with which it can be made. NPG is a particularly important scaffold because of its unique properties, including biofouling resistance and ease of modification. In this review, several different methods to synthesize NPG, along with varying modification approaches are described. These include the use of ternary alloys, immersion-reduction (chemical, electrochemical, hybrid), co-electrodeposition-annealing, and under-potential deposition coupled with surface-limited redox replacement of NPG with different metal nanoparticles (e.g., Pt, Cu, Pd, Ni, Co, Fe, etc.). The review also describes the importance of fully characterizing these bimetallic nanocomposites and critically analyzing their structure, surface morphology, surface composition, and application in electrochemical sensing of chemical and biochemical species. The authors attempt to highlight the most recent and advanced techniques for designing non-enzymatic bimetallic electrochemical nanosensors. The review opens up a window for readers to obtain detailed knowledge about the formation and structure of bimetallic electrodes and their applications in electrochemical sensing.

Use of a nano-porous gold film electrode modified with chitosan / polypyrrole for electrochemical determination of metronidazole in the Presence of Acetaminophen

This study, it was aimed to provide a sensitive, easy and selective method for designing Nano-porous gold film electrode (NPGF) electrode for simultaneous measurement of metronidazole (MT) and acetaminophen (AC). For this purpose, the NPGF electrode surface was modified with chitosan (CS) and poly pyrrole (PPY) by electrochemical method, and then CS and PPY modified NPGF (PPY-CS-NPGF) electrode were used to measure these drugs. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) are employed for the characterization of the attained PPY-CS-NPGF electrode. Using cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and chronoamperometry, the electrochemical behavior of MT was investigated with the modified electrode. By differential pulse voltammetry, linear ranges of concentration 0.005-100 μM with linear coefficients of 0.9898 and a detection limit of 0.0009 μM were obtained for MT. Finally, an electrochemical sensor was used to measure MT in a real sample, which yielded acceptable results. PPY-CS-NPGF electrodes have a wide linear range, high selectivity, sensitivity and stability and can be used successfully to determine these drugs.

Electrochemical non-enzymatic glucose sensors: recent progress and perspectives

This review summarizes recent advances in the development of electrocatalysts for non-enzymatic glucose detection. The sensing mechanism and influencing factors are discussed, and the perspectives and challenges are also addressed.

Recent advances in electrochemical non-enzymatic glucose sensors - A review

This review encompasses the mechanisms of electrochemical glucose detection and recent advances in non-enzymatic glucose sensors based on a variety of materials ranging from platinum, gold, metal alloys/adatom, non-precious transition metal/metal oxides to glucose-specific organic materials. It shows that the discovery of new materials based on unique nanostructures have not only provided the detailed insight into non-enzymatic glucose oxidation, but also demonstrated the possibility of direct detection in whole blood or interstitial fluids. We critically evaluate various aspects of non-enzymatic electrochemical glucose sensors in terms of significance as well as performance. Beyond laboratory tests, the prospect of commercialization of non-enzymatic glucose sensors is discussed.

Preparation, Modification, Characterization, and Biosensing Application of Nanoporous Gold Using Electrochemical Techniques

Nanoporous gold (np-Au), because of its high surface area-to-volume ratio, excellent conductivity, chemical inertness, physical stability, biocompatibility, easily tunable pores, and plasmonic properties, has attracted much interested in the field of nanotechnology. It has promising applications in the fields of catalysis, bio/chemical sensing, drug delivery, biomolecules separation and purification, fuel cell development, surface-chemistry-driven actuation, and supercapacitor design. Many chemical and electrochemical procedures are known for the preparation of np-Au. Recently, researchers are focusing on easier and controlled ways to tune the pores and ligaments size of np-Au for its use in different applications. Electrochemical methods have good control over fine-tuning pore and ligament sizes. The np-Au electrodes that are prepared using electrochemical techniques are robust and are easier to handle for their use in electrochemical biosensing. Here, we review different electrochemical strategies for the preparation, post-modification, and characterization of np-Au along with the synergistic use of both electrochemistry and np-Au for applications in biosensing.