Aptasensors Based on Graphene Field-Effect Transistors for Arsenite Detection

Abstract

All-electronic chemical sensors based on field-effect transistors (FETs) hold tremendous promise for rapid and sensitive detection of arsenic in groundwater. Their sensitivity, however, is fundamentally limited by a chemical gating mechanism where target ion charges are directly measured. We have developed a highly sensitive aptasensor, based on scalable graphene FETs, which relies on the conformational change of the negatively charged aptamer upon arsenite binding, offering a wide analytical range, from 0.05 to 1000 ppb, and with a 0.02 ppb detection limit. Circular dichroism spectroscopy studies confirmed the conformational change of the aptamer, and molecular dynamic studies further validated that arsenite had bound with the hairpin loop of the aptamer. This work provides a highly accurate chemical sensing platform for rapid detection of arsenic in drinking water.

Graphene-Based Field-Effect Transistors in Biosensing and Neural Interfacing Applications: Recent Advances and Prospects

“…The aptasensor array demonstrated exceptional sensing capabilities for the detection of Hg 2+ ions selectively in 100 pM to 100 nM concentration range within one second and with a LOD of 40 pM. Recently, Li et al 214 also demonstrated scalable GFET aptasensor arrays consisting of 100 GFETs for sensitive detection of arsenite (As 3+ ) ions (Figure 8D). The aptamer functionalized GFET for detection of As 3+ mainly relies on the conformationational change of the negatively charged aptamer upon interaction with As 3+ ions.…”

Unlocking the Potential of Field Effect Transistor (FET) Biosensors: A Perspective on Methodological Advances in Computational and Molecular Biology

“…This, in turn, has led to significant improvements in the performance of biosensors. Increasing use of computational tools in the study of gFETs [73,92,93] has demonstrated the predictive power of computational approaches in protein engineering for sensing applications.…”

Toward the Ultimate Limit of Analyte Detection, in Graphene-Based Field-Effect Transistors

“…Field-effect-transistor (FET)-based sensors are attractive platforms for biochemical diagnostics in point-of-care applications due to their high sensitivity, rapid detection, and relative ease of large-scale manufacture through harnessing available semiconductor fabrication infrastructure. − Recent developments in sensing have received an exciting boost through utilization of one- or two-dimensional materials with an intrinsically high surface area to volume ratio along with high charge carrier mobility, − facilitating superior sensitivity − as exemplified through the use of graphene. − For specificity of analyte detection, the related surfaces typically have attached linker molecules, e.g., 1-pyrenebutanoic acid N -hydroxysuccinimidyl ester (PBASE), followed by bioreceptors, such as aptamers (Ap) and enzymes, that are at a distance away from the surface (see Section S1 of the Supporting Information for related mechanisms) rather than direct adsorption onto the surface, , for specific binding to a target analyte ion. − The utilization of Ap, i.e., single-stranded DNA or RNA oligonucleotides, is attractive due to the possibility of high selectivity and ease of further modification (adaptation) from (to) various biologic as well as chemical functional groups − and has been extensively reviewed. − …”

“…10 μL of a range of PBASE concentrations (through mixing 1-pyrenebutanoic acid (Anaspec, Inc.) with dimethylformamide) was placed on the graphene, followed by 10 μL of T30695 Ap (from IDT Technologies, Inc., in a range of concentrations in deionized water). Ap was heated to 90 °C for 5 min and slowly cooled to room temperature to induce extended conformation . Subsequently, ethanolamine (EA) was used to passivate the unlinked left over PBASE.…”

“…Ap was heated to 90 °C for 5 min and slowly cooled to room temperature to induce extended conformation. 11 Subsequently, ethanolamine (EA) was used to passivate the unlinked left over PBASE. Subsequently, the Pb 2+ analyte was added to the GFET through Pb(NO 3 ) 2 dissolved in DI water at various concentration levels.…”