Robust label-free microRNA detection using one million ISFET array

Abstract

Detection of nucleic acid molecules is one of the most pervasive assays in biology, medicine, and agriculture applications. Currently, most comely used DNA/RNA detection platforms use fluorescence labeling and require lab-scale setting for performing the assay. There is a need for developing less expensive, label-free, and rapid detection of biomolecules with minimal utilization of resources. Use of electrical approaches for detection of biomolecules by utilizing their inherent charge is a promising direction for biosensing assays. Here, we report a 1024 × 1024 array of Ion Sensitive Field Effect Transistors (ISFET) as label free sensors for detection of nucleic acid molecules. Using PNA probe functionalized on these ISFET array, we robustly detected miRNA Let-7b by measuring changes in drain current after hybridization of target molecules with concentration as low as 1 nM. We demonstrate that mismatched or non-complementary target molecules resulted in statistically smaller changes. Most importantly, the high-density sensor array shows unprecedented reliability and robustness with P values <0.0001 for all experiments. Practical implementation of this platform could have a wide range of applications in high-throughput nucleic acid genotyping, detection of amplified pathogenic nucleic acid, detection of cell-free DNA, and electrical readouts for current hybridization-based DNA biomolecular assays.

Recent advances in ion‐sensitive field‐effect transistors for biosensing applications

“…The ISFETs array achieved reliable detection of miRNA Let-7b, which is a cancer biomarker, after hybridization of target molecules with a concentration as low as 1 nM. [130] The combination of the ISFET array and microfluidic system also enables the detection of DNA base pairing, which is one of the most critical steps in gene sequencing. In Wu and co-workers, a biosensing array chip that contains more than 13 million sensitive units were designed to track DNA base pairs.…”

“…The ISFETs array achieved reliable detection of miRNA Let‐7b, which is a cancer biomarker, after hybridization of target molecules with a concentration as low as 1 nM. [ 130 ]…”

Ultrasensitive Detection of Dopamine, IL‐6 and SARS‐CoV‐2 Proteins on Crumpled Graphene FET Biosensor

“…[ 2 ] FET‐based biosensors allow label‐free and highly sensitive biomolecular detection on integrated lab‐on‐a‐chip systems. Detection of pH, nucleic acids, proteins, and other biomarkers have been reported using FET biosensor with many different channel materials such as conventional silicon, [ 3 , 4 ] nanowire, [ 5 , 6 ] and 2D materials. [ 7 , 8 ] Among those, graphene is an attractive material due to its unique mechanical, chemical, and electrical properties.…”

Advances in field-effect biosensors towards point-of-use

“…Figure 1(b) shows the number of bioFETs per chip for various channel materials over the years. Planar silicon-based bioFETs have achieved an impressive integration of over a million bioFETs on a single chip [14][15][16][17][18]. Carbon nanotube (CNT)-based bioFETs have also shown a significant progress in packing density, reaching ∼10 000 bioFETs per chip [19].…”