Progress in Medical Application of Silicon Nanowire Field Effect

Tube Biosensor

Xiang Chen

School of Materials Science and Engineering, East China Jiaotong University, Nanchang, Jiangxi, 330013, China

Keywords: Silicon Nanowires (SiNW), Field Effect Transistor (FET), Biosensor, Biomedical Applications.

Abstract: In recent years, the silicon nanowire field effect transistor (SiNW FET) biosensor with a single crystal silicon

core and one-dimensional nanostructure has become a hot research object, and is widely used in biomedical

detection, suitable for the detection of biomarkers. In this paper, the applications of SiNW FET biosensors in

the medical field in recent years are critically reviewed. Firstly, the basic structure, working mechanism, and

the two preparation methods of "top-down" and "bottom-up" of SiNW FET biosensors are briefly introduced,

especially the specific sensing mechanism of SiNW FET biosensors. Then, the three application directions of

SiNW FET biosensors currently used in the biomedical field are summarized, including the detection of

proteins, DNA/RNA, and viruses, and the limitations of the current research are pointed out. Finally, the

possible research directions in the future are proposed, such as surface modification, flexible substrate

integration, and nanotechnology. The challenges of SiNW FET biosensor development in the future are

discussed extensively.

1 INTRODUCTION

In recent years, the silicon nanowire field effect

transistor (SiNW-FET) biosensors have become

widely popular research objects due to their

advantages, such as extensive customizable

parameters, high carrier mobility, ideal subthreshold

slope, and nanoscale sensitivity. Yong et al. (2021)

found that the lowest detectable concentration of

HBsAg using SiNW-FET was 100 fg/mL,

demonstrating its characteristic of ultra-high

sensitivity. Due to its nanoscale size, the SiNW-FET

biosensor is highly suitable for detecting most

biomarkers, such as proteins, DNA/RNA, cells, and

viruses. This makes the SiNW-FET biosensor have

great application value and advantages in the medical

field, providing accurate detection for the treatment

of many diseases and thereby increasing the

possibility of curing diseases.

In 2001, Field-effect transistors that utilize silicon

nanowires were first reported to be applied in the

detection of biological and chemical molecules (Li et

al., 2022; Vu et al., 2023), surface-modified silica

samples and SiNW-FET channels using silane-PEG,

enabling precise quantification of cTnI and other

https://orcid.org/0009-0002-6775-028X

protein biomarkers at an ultra-low level. In the field

of medicine, the detection of various biomarkers by

sensors has been successfully applied and has broad

prospects for medical applications.

This paper first introduces the basic structure,

preparation method, and working mechanism of the

SiNW-FET biosensor. Subsequently, the medical

application progress of these biosensors in the

detection of proteins, DNA/RNA, and viruses was

summarized. Based on the existing research methods

and achievements at present, some possible solutions

were provided for other medical application fields in

the future.

2 THE BASIC STRUCTURE AND

WORKING MECHANISM OF

SINW FET BIOSENSOR

2.1 Structure of SiNW-FET Biosensor

Figure 1 shows functionalized silicon nanowires with

source and drain electrodes at both ends. Specific

antibodies are coated on the silicon nanowires, which

498

Chen, X.

Progress in Medical Application of Silicon Nanowire Field Effect Tube Biosensor.

DOI: 10.5220/0013828300004708

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 2nd International Conference on Innovations in Applied Mathematics, Physics, and Astronomy (IAMPA 2025), pages 498-502

ISBN: 978-989-758-774-0

can bind specifically to the target antigen and cause

changes in electrical signals, manifested as changes

in source-drain current. After specific binding with

the antigen, the surface charge density changes,

which in turn affects the conductivity of SiNW.

Measuring the current can help detect the presence of

the target antigen.

Figure 1: Structure of SiNW FET biosensor (Hadded et al., 2025)

Figure 2: Detection principle of SiNW-FET biosensor (Li et al., 2022)

As shown in Figure 1, SiNW FET is a gate voltage

semiconductor control device. Currently, the two

main preparation methods for SiNW FET chips are

"top-down" and "bottom-up". The "top-down"

method has a mature preparation process, using

advanced technologies such as nanomanufacturing

and photolithography, which can prepare SiNWs with

diameters of tens of nanometers from silicon wafers

in specific environments, allowing for very large-

scale integration. However, the top silicon layer's

patterning and etching can result in geometric

changes, which affect electrical parameters and

require controlled conditions to reduce variations.

The "bottom-up" approach can synthesize SiNWs

with diameters ranging from a few nanometers to

several hundred nanometers, and their quasi one-

dimensional properties enable them to exhibit

outstanding performance in fields such as electronics,

optoelectronics, energy, and biomedical applications.

However, there are technical challenges in achieving

large-scale reproducible production (Tintelott et al.,

2021; Arjman et al., 2022). In addition, silicon

nanowires contain specific receptors that can bind to

target biomarkers. Different types of SiNW FET

biosensors can bind to different target molecules, and

specific receptors coated on silicon nanowires can be

customized for the target molecules that need to be

recognized. In terms of biological detection,

customizable SiNW FET biosensors can be surface-

modified according to specific biomarker molecules,

making them widely applicable to various detection

needs.

Progress in Medical Application of Silicon Nanowire Field Effect Tube Biosensor

499

2.2 The Working Mechanism of SiNW-

FET

Figure 2 illustrates this, when charged biomarker

molecules bind specifically to specific receptor

(probe) molecules on silicon nanowires, the

conductivity of SiNW changes. Among them,

changes in current between the source and drain

electrodes can be recorded by the semiconductor

analyzer. If biomarker molecules are negatively

charged, their binding with specific receptor (probe)

molecules will increase conductivity and current. On

the contrary, if biomarker molecules are positively

charged, their binding with specific receptor (probe)

molecules will reduce conductivity and current (Li et

al., 2022).

From the perspective of changes in charge

density, the sensing mechanism of SiNW FET is

actually to recognize different biomarker molecules

by binding to them, resulting in changes in the electric

field on the surface of SiNW (Zhang, & Ning, 2012).

The SiNW-FET biosensor has successfully measured

the concentration of miRNAs at the fly molar level

through surface modification, also known as surface

modification, which is an important method for

preparing SiNW FET biosensors with specific

recognition functions (Vu et al., 2022).

3 APPLICATION SCENARIOS

AND CASE ANALYSIS IN THE

MEDICAL FIELD

3.1 Protein Detection

Protein is a kind of nutrient and plays an important

role in human life activities. Protein is a component

of many substances, such as most hormones in the

human body, the protein coat of viruses, and

ribosomes in bacteria. Therefore, the precise

detection of proteins is a crucial aspect in medical

applications.

The detection of Cys-C in the human body is of

great significance for the prevention of acute kidney

injury (AKI). Blood is one of the bodily fluids that

contains the cysteine protease inhibitor Cys-C. It is

considered to be an early indicator of AKI that is

linked to glomerular filtration rate (GFR) (Hu et al.,

2023). Hu et al. (2023) concluded that it is evident

that the SiNW-FET biosensor they prepared has

advantages in detecting the biomarker Cys-C for early

renal failure. The detection limit is 0.25 ag/mL when

the Cys-C concentration range is 1 ag/mL and 1

ng/mL, enabling linear detection to be performed. Liu

et al. (2023) fabricated a single-molecule device

based on SINW-FET by performing point

modifications and constrained reactions on the side

walls of SiNW. The experimental results show that

the biosensor constructed using high-performance

SiNW-FET molecular nanocircuits has high temporal

resolution and sensitivity. Complex polymorphic

current signals can be observed in the low DQ47

concentration range (5-500 nm) at a temporal

resolution of 17μs. Their SiNW-FET single-molecule

platform is mentioned as being suitable for various

label-free biological detections with a single-

molecule resolution.

Glycated hemoglobin A1c (HbA1c) is an

indicator for measuring the long-term blood glucose

control of complications related to chronic diabetes.

The SiNW-FET sensor can rapidly determine the

level of HbA1c in human blood and is suitable for

immediate diagnosis (Vu et al., 2022). Anand et al.

(2021) pointed out that compared with the

determination methods carried out in professional

laboratories, the SiNW-FET sensor has the

advantages of low cost, rapidity, and convenience. It

uses A short synthetic engineered DNA or RNA

oligonucleotide called an aptamer. Self-assembling

into a unique recognition motif is capable of

capturing target molecules with high affinity and

specificity.

A large number of relevant studies have shown

that SiNW-FET biosensors have great potential and

can gradually be more widely applied in the detection

and targeted therapy of substances composed of

proteins in organisms in the future.

3.2 Detection of DNA/RNA

The presence of deoxyribonucleic acid (DNA) and

ribonucleic acid (RNA) in the cells of all living

organisms is crucial for protein encoding and storage

of genetic information (Lu et al., 2024). Circulating

tumor DNA (ctDNA) is a method that shows promise

for detecting cancer, targeted therapy, and prognosis.

Li et al. (2023) modified DNA probes on SiNW

arrays through silanization, and the experimental

results showed that Human serum samples were

successfully identified by the SiNW-FET biosensor

that was prepared, demonstrating promising clinical

application potential in the future.

At present, biosensors used for detecting DNA

mainly use peptide nucleic acid (PNA) as probes,

which specifically bind to ctDNA to capture target

DNA. The biosensor's surface is bonded to the PNA

probe using covalent bonding modification

IAMPA 2025 - The International Conference on Innovations in Applied Mathematics, Physics, and Astronomy

500

technology, and a stable complex is formed by base

complementary pairing principle and DNA-specific

binding (Lu, H. et al., 2024). When a normal ctDNA

(ncDNA) solution is dropped onto the electrode, there

is almost no potential change. This new technique

uses complementary pairing of DNA probe bases to

achieve excellent selectivity and ultra-high

sensitivity, and can detect abnormal ctDNA

methylation levels by chemically modifying SiNW

FET biosensors (Wang et al., 2022). Yusoh et al.

(2021) used p-type silicon on insulator (SOI) wafers

to fabricate SiNW biosensors, and Based on the

results, a 10-wire SiNW device that was etched with

25% by weight TMAH and 10% by volume IPA was

the most sensitive, reaching 82.8 AM-1, with a

minimum LOD of 1.93 fM. They successfully

detected dengue fever DNA and pointed out that the

sensitivity of SiNW FET DNA biosensors was

affected by three factors: wire quantity, wire size, and

surface roughness.

The diagnosis of various diseases is greatly

affected by microRNA (miRNA) sensing, especially

cancer. To date, SiNW FET biosensors have been

able to accurately assess the concentration of

miRNAs at the femtomolar level through a simple

surface modification method. By using mSAM of

silane PEG-NH on the SiNW surface, Vu et al. (2022)

enhanced the performance of SiNW FET DNA

biosensors for miRNA detection, resulting in more

significant signal changes of DNA/RNA complexes

under high ionic strength conditions and improved

detection accuracy.

The SiNW FET biosensor for detecting

DNA/RNA has great application value and potential,

which may provide new ideas and methods for the

diagnosis and treatment of major diseases and

cancers.

3.3 Virus Detection

The virus is a microbial pathogen whose genetic

material contains only one type of nucleic acid. It

must parasitize within living cells and is very

common in the human living environment. For

detecting whether the human body is infected with a

virus, the currently widely used method is antigen

kits, such as the COVID-19 rapid test kit (Li et al.,

2021).

The SiNW-FET biosensor, which has the

advantages of real-time monitoring and being label-

free, can be mass-produced in the semiconductor

industry and is therefore suitable for the convenient

detection of COVID-19. Wang et al. used anti-IL-6

antibodies or anti-IL-6 aptamer probes as specific

biometric elements on SiNW-FETs and concluded

that using aptamer-functionalized SiNW-FETs to

identify IL-6 levels in patients with severe COVID-

19 has the potential to be significant. However,

further research is necessary to confirm if aptamer-

functionalized SiNW-FET can fulfill the clinical

requirements for determining the severity of COVID-

19 patients (Li et al., 2021).

Dengue fever is a viral infection transmitted by

arthropods that is prevalent worldwide and belongs to

the genus Flavivirus of the Flavivirus family. Zhang

et al. (2010) reported that this SiNW-FET biosensor

is powered by electricity and integrates biomolecules

with technology that is compatible with metal-oxide-

semiconductor (CMOS), facilitating the detection of

charge changes when the target analyte is bound to a

fixed probe. The experimental results show that, to

demonstrate the concept, the SiNW sensor was

combined with RT-PCR technology, using nucleic

acid hybridization and electrical detection, has been

developed for label-free, specific, rapid, and highly

sensitive detection of dengue virus in research.

The SiNW-FET biosensor is used for virus

detection and can provide a rapid and convenient

detection method for influenza and viral infectious

diseases, as well as a specific treatment plan for a

possible disease, which has great potential.

4 CONCLUSION

This article summarizes the application of SiNW FET

biosensors in the medical field in recent years. Firstly,

the preparation methods and working mechanisms of

SiNW FET biosensors are introduced, mainly

involving surface modification, "top to bottom" and

"bottom to top" technologies, nano manufacturing,

etc. The customizable specificity, label-free nature,

and high detection efficiency of SiNW FET

biosensors have excellent development prospects in

the future. The examples given in this article reflect

the wide application of SiNW FET biosensors in

targeted detection and treatment of more tumor cells,

detection of new viruses, and determination of animal

health status.

At present, SiNW FET biosensors have great

potential and application value in the medical field,

but there are still limitations, such as some limitations

in medical care point diagnosis and in addressing the

inherent stiffness and brittleness of wearable silicon

applications. However, it is expected that in the

future, surface modification, flexible substrate

integration, and nanotechnology will continue to

develop to overcome these limitations.

Progress in Medical Application of Silicon Nanowire Field Effect Tube Biosensor

501

In summary, SiNW FET biosensors are

convenient, fast, highly sensitive, and specific for

detecting proteins in medical applications.

DNA/RNA、 Viruses provide an efficient and novel

solution, demonstrating their enormous potential for

clinical applications. Future research directions may

include surface modification, nanotechnology, etc., to

overcome wearable applications, as well as the use of

SiNW FET biosensors to detect biomarkers of various

other diseases and assist in treatment. They have

broad research value and good development

prospects.

REFERENCES

Anand, A., Chen, C.Y., Chen, T.H., Liu, Y.C., Sheu, S.Y.,

Chen, Y.T., 2021. Detecting glycated hemoglobin in

human blood samples using a transistor-based

nanoelectronic aptasensor. Nano Today, 41: 101294.

Hadded, A., Ben Ayed, M., Alshaya, S.A., 2025. An FPGA-

Based SiNW-FET Biosensing System for Real-Time

Viral Detection: Hardware Amplification and 1D CNN

for Adaptive Noise Reduction. Sensors, 25(1): 236.

Hu, J., Li, Y., Zhang, X., Wang, Y., Zhang, J., Yan, J.,

Zhang, Q., 2023. Ultrasensitive silicon nanowire

biosensor with modulated threshold voltages and ultra-

small diameter for early kidney failure biomarker

cystatin C. Biosensors, 13(6): 645.

Li, D., Chen, H., Fan, K., Labunov, V., Lazarouk, S., Yue,

X., Wang, G., 2021. A supersensitive silicon nanowire

array biosensor for quantifying tumor marker ctDNA.

Biosensors and Bioelectronics, 181: 113147.

Li, H., Li, D., Chen, H., Yue, X., Fan, K., Dong, L., Wang,

G., 2023. Application of silicon nanowire field effect

transistor (SiNW-FET) biosensor with high sensitivity.

Sensors, 23(15): 6808.

Li, H., Wang, S., Li, X., Cheng, C., Shen, X., Wang, T.,

2022. Dual-channel detection of breast cancer

biomarkers CA15-3 and CEA in human serum using

dialysis-silicon nanowire field effect transistor.

International Journal of Nanomedicine, 17: 6289.

Liu, W., Chen, L., Yin, D., Yang, Z., Feng, J., Sun, Q., Guo,

X., 2023. Visualizing single-molecule conformational

transition and binding dynamics of intrinsically

disordered proteins. Nature Communications, 14(1):

5203.

Lu, H., Wang, D., Huang, G., Ma, Q., Zhang, Y., Mei, M.,

Shui, L., 2024. Label-free identification of DNA single-

base mutation for clinical diagnostics based on

plasmonic SiNW@AgNP arrays. Sensors and

Actuators B: Chemical, 401: 135005.

Tintelott, M., Pachauri, V., Ingebrandt, S., Vu, X.T., 2021.

Process variability in top-down fabrication of silicon

nanowire-based biosensor arrays. Sensors, 21(15):

5153.

Vu, C.A., Lai, H.Y., Chang, C.Y., Chan, H.W.H., Chen,

W.Y., 2022. Optimizing surface modification of silicon

nanowire field-effect transistors by polyethylene glycol

for MicroRNA detection. Colloids and Surfaces B:

Biointerfaces, 209: 112142.

Vu, C.A., Su, Y.T., Wang, J.S., Chang, C.Y., Hu, W.P.,

Huang, C.J., Chen, W.Y., 2023. Comparing surface

modification methods for silicon nanowire field-effect

transistor biosensors for diagnosis applications: A case

study of cardiac troponin I. Colloids and Surfaces A:

Physicochemical and Engineering Aspects, 676:

132146.

Wang, K., Peng, Z., Lin, X., Nian, W., Zheng, X., Wu, J.,

2022. Electrochemical biosensors for circulating tumor

DNA detection. Biosensors, 12(8): 649.

Yong, S.K., Shen, S.K., Chiang, C.W., Weng, Y.Y., Lu,

M.P., Yang, Y.S., 2021. Silicon nanowire field-effect

transistor as label-free detection of hepatitis B virus

proteins with opposite net charges. Biosensors, 11(11):

442.

Yusoh, S.N., Yaacob, K.A., 2021. Study on the physical

properties of a SiNW biosensor for the sensitivity of

DNA detection. Materials, 14(19): 5716.

Zhang, G.J., Ning, Y., 2012. Silicon nanowire biosensor

and its applications in disease diagnostics: A review.

Analytica Chimica Acta, 749: 1–15.

Zhang, G.J., Zhang, L., Huang, M.J., Luo, Z.H.H., Tay,

G.K.I., Lim, E.J.A., Chen, Y., 2010. Silicon nanowire

biosensor for highly sensitive and rapid detection of

Dengue virus. Sensors and Actuators B: Chemical,

146(1): 138–144.

IAMPA 2025 - The International Conference on Innovations in Applied Mathematics, Physics, and Astronomy

502