Highly Sensitive and Wearable In₂O₃ Nanoribbon Transistor Biosensors with Integrated On-Chip Gate for Glucose Monitoring in Body Fluids

Abstract

Nanoribbon- and nanowire-based field-effect transistor (FET) biosensors have stimulated a lot of interest. However, most FET biosensors were achieved by using bulky Ag/AgCl electrodes or metal wire gates, which have prevented the biosensors from becoming truly wearable. Here, we demonstrate highly sensitive and conformal InO nanoribbon FET biosensors with a fully integrated on-chip gold side gate, which have been laminated onto various surfaces, such as artificial arms and watches, and have enabled glucose detection in various body fluids, such as sweat and saliva. The shadow-mask-fabricated devices show good electrical performance with gate voltage applied using a gold side gate electrode and through an aqueous electrolyte. The resulting transistors show mobilities of ∼22 cm V s in 0.1× phosphate-buffered saline, a high on-off ratio (10), and good mechanical robustness. With the electrodes functionalized with glucose oxidase, chitosan, and single-walled carbon nanotubes, the glucose sensors show a very wide detection range spanning at least 5 orders of magnitude and a detection limit down to 10 nM. Therefore, our high-performance InO nanoribbon sensing platform has great potential to work as indispensable components for wearable healthcare electronics.

Flexible Electrochemical Bioelectronics: The Rise of In Situ Bioanalysis

“…Glucose detection (3.3–10.9 mmol) was obtained by direct measurement of the Dirac point shift and the drain‐source current. As illustrated in Figure a, a flexible glucose sensor was developed based on In 2 O 3 nanoribbon FETs with a fully integrated on‐chip gold side gate . The In 2 O 3 nanoribbon‐based source and drain electrodes were modified with the GOx‐loaded chitosan/CNT matrix to achieve a wide detection range (5 orders of magnitude) and an ultralow detection limit (10 nmol).…”

Stretchable Sensors for Nanomolar Glucose Detection

“…Table S3 (Supporting Information) compares the figures of merit obtained in this paper with other published works investigating flexible, glucose sensors. The range of detection achieved using the flexible, prestrained electrodes is relevant for monitoring blood sugar via sweat in diabetic patients, as well as for noninvasive methods utilizing saliva, tears, or any application that requires detection of small changes in glucose concentration 38–40…”

Reusable, Non-Invasive, and Ultrafast Radio Frequency Biosensor Based on Optimized Integrated Passive Device Fabrication Process for Quantitative Detection of Glucose Levels

“…A biosensor can convert different concentrations of glucose into corresponding electrical signals for output, which has advantages of high accuracy, fast analysis, low cost, good repeatability, simple operation and high specificity by comparing with traditional detection methods [10][11][12][13][14][15][16]. With the aid of chips, microfluidics systems and labs-on-a-chip, biosensor technology have developed rapidly and can be divided into electrochemical biosensors and optical biosensors based on the type of signal conversion [17][18][19][20][21][22][23][24][25][26]. Electrochemical biosensors enable the detection of biomarkers by adding specific enzymes on the electrodes, which has many advantages, such as high sensitivity, simple operation and cost-effective [27][28][29].…”