Ultrasensitive Silicon Nanowire Biosensor with Modulated Threshold Voltages and Ultra-Small Diameter for Early Kidney Failure Biomarker Cystatin C

Abstract

Acute kidney injury (AKI) is a frequently occurring severe disease with high mortality. Cystatin C (Cys-C), as a biomarker of early kidney failure, can be used to detect and prevent acute renal injury. In this paper, a biosensor based on a silicon nanowire field-effect transistor (SiNW FET) was studied for the quantitative detection of Cys-C. Based on the spacer image transfer (SIT) processes and channel doping optimization for higher sensitivity, a wafer-scale, highly controllable SiNW FET was designed and fabricated with a 13.5 nm SiNW. In order to improve the specificity, Cys-C antibodies were modified on the oxide layer of the SiNW surface by oxygen plasma treatment and silanization. Furthermore, a polydimethylsiloxane (PDMS) microchannel was involved in improving the effectiveness and stability of detection. The experimental results show that the SiNW FET sensors realize the lower limit of detection (LOD) of 0.25 ag/mL and have a good linear correlation in the range of Cys-C concentration from 1 ag/mL to 10 pg/mL, exhibiting its great potential in the future real-time application.

Recent Advances in Nanowire-Based Wearable Physical Sensors

“…Fabricating or assembling planar NW arrays on a large scale compatible with planar device fabrication and integration is crucial for developing novel NW-based electronic devices, and many pioneering efforts have been devoted to this goal. For example, some direct fabrication methods include using electron beam lithography (EBL) or nano-imprint lithography (NIL) to pattern NWs and then dry or wet etching [66][67][68][69], using epitaxial growth techniques and the vapor-liquid-solid (VLS) mechanism to grow in-plane NW with controlled orientations [70][71][72]. Furthermore, some assembly strategies include using solution flow [73], shear force guidance [74], electric/magnetic field guidance [75,76], etc., to assemble NWs into planar uniform arrays [77].…”

Stencil-Based Selective Surface Functionalization of Silicon Nanowires in 3D Device Architectures for Next-Generation Biochemical Sensors

“…Similarly, the augmented surface-to-volume ratio and miniature size of Si NWs enable highly sensitive detection of gases, biological molecules, and cells, along with tissue-based engineering strategies. ,− A few examples include metal ions, chemical gases such as hydrogen, key biomarkers, and various biological antigens. ,− Furthermore, functionalized Si NWs hold the potential for the detection of key biomarkers for conditions such as wound healing and cancer. For example, the elevated levels of fibroblast growth factor (FGF-2) in tumor conditions are often a sign that the cancer is more aggressive or likely to progress at a faster rate.…”

Ultrasensitive 3D Stacked Silicon Nanosheet Field-Effect Transistor Biosensor with Overcoming Debye Shielding Effect for Detection of DNA

“…In particular, silicon nanowire field effect (SiNW-FET) biosensors exhibit great potential because of their high surface-to-volume ratio (S/V) and ease of surface modification [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. They enable us to achieve sensing detection by altering the probe molecules on the nanosensing surface and employing the gate pressure change caused by the probe’s attachment to the target molecule [ 25 ].…”

“…Biosensors 2024, 14, x FOR PEER REVIEW 2 of 14 altering the probe molecules on the nanosensing surface and employing the gate pressure change caused by the probe's attachment to the target molecule [25]. However, the Debye shielding of molecular charges by counterions in solution would occur in the FET-based biosensors, which would lower the detection limit [26,27].…”