Review—Recent Advances in Microfabrication, Design and Applications of Amperometric Sensors and Biosensors

Abstract

Over the past decade, the development of amperometric sensors and biosensors using microfabrication techniques has gained considerable attention. This interdisciplinary approach aims at bringing together scientific fields such as: chemistry, physics, engineering and biology to achieve devices’ miniaturization, integration and automatization. Among the technologies that have been reviewed for the fabrication of the microelectrodes, the most common are: soft lithography and microfabrication techniques, such as physical vapor deposition of different metals, photolithography, chemical wet etching method and anodic bonding process. The required parameters in the design of a microfabricated electrode array, such as inter-electrode distance, the three-electrode system, and the role of each electrode have been intensively discussed. This review provides an overview about the state-of-the-art microfabrication devices and their applications, as well as the recent advances in the fabrication of microelectrodes as transducers for amperometric sensors, immunosensors and biosensors with various applications in environmental, biomedical and pharmaceutical fields.

Paving the Way for a Green Transition in the Design of Sensors and Biosensors for the Detection of Volatile Organic Compounds (VOCs)

“…For example, the latest results in biotechnology are opening to the possibility of designing highly selective biosensors by tuning the affinity of the biological receptors to selected VOCs thanks to gene editing techniques [ 203 , 204 ]. Additionally, progress in microfabrication can lead to a substantial decrease in production costs, to large scale fabrication of nominally identical structures, and to the possibility of integrating different sensors and biosensors [ 205 ]. Lastly, to fully attain the sustainable characteristics needed for sustainable development, a life cycle assessment (LCA), claimed to be the best framework for assessing the potential environmental impacts of products [ 206 ], must be also determined for all sensors and biosensors before being brought to the market.…”

Wet etching in β-Ga2O3 bulk single crystals

“…51 There are two different cases; one is electrochemical etching, and the other is electroless etching. 52–54 In both processes, free carriers and the electrolyte are involved, while the former requires applied potential. In principle, both electrons and holes can cause the decomposition of the solid.…”

Inkjet Printing: A Viable Technology for Biosensor Fabrication

“…Although electrostatic inkjet printers and electrohydrodynamic inkjet printers can produce nano-sized spots, both of the printers are limited to conductive inks only [65][66][67]. Furthermore, photolithography allows for high-resolution patterning at the expense of high cost, requiring multiple steps such as mask preparation, photopatterning, and etching processes [68,69]. Decades of extensive research in the field of printing technologies have led to a major diversification in the number of developed printing techniques.…”