Microcantilevers and organic transistors: two promising classes of label-free biosensing devices which can be integrated in electronic circuits

Abstract

Most of the success of electronic devices fabricated to actively interact with a biological environment relies on the proper choice of materials and efficient engineering of surfaces and interfaces. Organic materials have proved to be among the best candidates for this aim owing to many properties, such as the synthesis tunability, processing, softness and self-assembling ability, which allow them to form surfaces that are compatible with biological tissues. This review reports some research results obtained in the development of devices which exploit organic materials' properties in order to detect biologically significant molecules as well as to trigger/capture signals from the biological environment. Among the many investigated sensing devices, organic field-effect transistors (OFETs), organic electrochemical transistors (OECTs) and microcantilevers (MCLs) have been chosen. The main factors motivating this choice are their label-free detection approach, which is particularly important when addressing complex biological processes, as well as the possibility to integrate them in an electronic circuit. Particular attention is paid to the design and realization of biocompatible surfaces which can be employed in the recognition of pertinent molecules as well as to the research of new materials, both natural and inspired by nature, as a first approach to environmentally friendly electronics.

Organic bioelectronics probing conformational changes in surface confined proteins

“…The initial structure of the AV-Biotin complex was obtained from the Protein Data Bank (PDB), entry 2AVI58. To increase the structure confidence level (to correct missing hydrogen atoms, incomplete side chains and loops, ambiguous protonation states and flipped residues) the 2AVI crystal was first pre-treated using the Schrödinger’s Protein Preparation Wizard (Version 9.5)59.…”

Fast-switching all-printed organic electrochemical transistors

“…Conversely, in the (EG)OFETs field-effect gating provide charge accumulation only along a thin sheet of the semiconducting layer. Printable or printed OECTs have been realized and reported previously for various applications, such as logic circuits [14], sensors [15,16] and active matrix addressed displays [17,18]. They typically suffer from non-symmetric switching characteristics, i.e.…”

Alkynylation of Aldehydes and Ketones Using the Bu4NOH/H2O/DMSO Catalytic Composition: A Wide‐Scope Methodology

“…Since their discovery, a remarkable enhancement in the performance of OTFTs has been accomplished by improvements in both materials and processing such that OTFTs now have charge carrier mobilities comparable to or higher than that of amorphous silicon 1–3. The utility of OTFTs has been demonstrated in flexible sensors,4, 5 memories,6 and in the driving circuitry of organic displays 7. For complementary circuits (CMOS), ideally both p‐ and n‐type OTFTs are patterned with reliable performance on a flexible substrate using solution‐based methods such as stamping, ink‐jet printing, Gravure printing, or solution‐shearing.…”