Ten Years Progress of Electrical Detection of Heavy Metal Ions (HMIs) Using Various Field-Effect Transistor (FET) Nanosensors: A Review

Abstract

Heavy metal pollution remains a major concern for the public today, in line with the growing population and global industrialization. Heavy metal ion (HMI) is a threat to human and environmental safety, even at low concentrations, thus rapid and continuous HMI monitoring is essential. Among the sensors available for HMI detection, the field-effect transistor (FET) sensor demonstrates promising potential for fast and real-time detection. The aim of this review is to provide a condensed overview of the contribution of certain semiconductor substrates in the development of chemical and biosensor FETs for HMI detection in the past decade. A brief introduction of the FET sensor along with its construction and configuration is presented in the first part of this review. Subsequently, the FET sensor deployment issue and FET intrinsic limitation screening effect are also discussed, and the solutions to overcome these shortcomings are summarized. Later, we summarize the strategies for HMIs’ electrical detection, mechanisms, and sensing performance on nanomaterial semiconductor FET transducers, including silicon, carbon nanotubes, graphene, AlGaN/GaN, transition metal dichalcogenides (TMD), black phosphorus, organic and inorganic semiconductor. Finally, concerns and suggestions regarding detection in the real samples using FET sensors are highlighted in the conclusion.

Femtomolar Level-Specific Detection of Lead Ions in Aqueous Environments, Using Aptamer-Derivatized Graphene Field-Effect Transistors

“…The underlying mechanism related to FET-based detection is broadly understood − ,, and involves the modulation of the electrical current ( I ds ) in the graphene channel between the drain and source electrodes, by the sensing moiety, such as the Pb 2+ ionwhich has been considered here as attached to the Ap yielding the APG. When there is no attached Pb 2+ , there would be a particular gate voltage ( V g ) where the I ds may be tuned to a minimum: blue trace in Figure d.…”

The Progress of Research into Flexible Sensors in the Field of Smart Wearables

“…With the development of advanced materials and fabrication technologies, flexible sensors with multifunctional sensory capabilities are becoming increasingly popular in the field of smart wearables. Furthermore, the combination of elastic substrates with conductive fillers, such as graphene [ 91 ], carbon nanotubes [ 92 ], metals/semiconductors [ 93 ], and conductive polymers [ 94 ], has been widely investigated. However, most of these sensors suffer from the disadvantages of a low elasticity, insufficient flexibility, and poor durability due to the rigidity of their materials.…”

Sensors Based on the Carbon Nanotube Field-Effect Transistors for Chemical and Biological Analyses

“…The accuracy of Cu 2+ concentration prediction was expressed by the correlation coefficient (R 0 ) of 0.985 and the root means square error between the actual Cu 2+ ion concentration and the predicted Cu 2+ concentration of 0.038. Based on this method, Wang et al [ 210 ] used similar sensing methods to prepare SWCNT-FET sensors for detecting and monitoring Cd 2+ in feed. Similar to Cu 2+ , Cd 2+ also lacks the specific DNAzyme, and the interference of Cd 2+ , Hg 2+ , Pb 2+ and other metal ions will also hinder the recognition.…”

“…Compared with the DNAzyme, aptamer (a single-stranded DNA) is better for the sensor recognition components because the aptamer changes its structure only when the target exists. Wang et al [ 210 ] prepared a G-quadruplex aptamer (G4-DNA) and complementary CS-DNA functionalized FET chemosensor to determine Pb 2+ ions, and can be reused. The G4-DNA is a functional DNA molecule with a specific binding affinity to Pb 2+ .…”