High-Throughput Screening Through Poly-SiNW FETs for Ultrasensitivity and Selectivity, Label-Free and Real-Time Biosensing

The rising demands for ultrasensitive, selective, label-free, and real-time biomolecules screening nanotechnology device is a concern. It is a necessity and concerned for the development of such device in the diagnosis and direct monitoring of biomolecules like cancers, diseases, flu and emergency outbreak, especially in the developing nations. Therefore, the need for the development of such a novel detection mechanism with ultrasensitivity, selectivity, label-free and real-time screening is paramount. Since, the conventional mechanisms available require robust approaches with lengthy screening time, less sensitivity, specificity, and high-cost burden. Therefore, in this research, we developed and fabricated such a device that will try to solve the issues mentioned in the conventional mechanisms. The polycrystalline silicon nanowire (poly-SiNW) device in a field-effect set-up has positively demonstrated experimentally to the issues mentioned for ultrasensitive, highly selective, label-free and real-time detection of deoxyribonucleic acid, protein, lipid, etc., as well as small molecules at low concentration. It is a device highly sensitive to be used to detect biomolecules in real-time. However, the manufacturing technique relies on highly expensive tools for mass production, such as the e-beam lithography, and expensive substrates like the silicon-on-insulator which poses the hurdle of cheap and fast production of the devices that can be used for both clinical and research purposes.
The significant drawbacks in this conventional fabrication, the “bottom-up” nanostructures resulting in too much complex integration are addressed. The “top-down” fabrication explored, gives rise to the pathway for high–density and –quality nanoscale sensors that incorporate into silicon-based signal processing and communication circuits. Thus, utilizing the used of local oxidation of silicon process. This fabrication approach is entirely compatible with complementary metal-oxide-semiconductor technology, avoiding the needs for expensive lithography tools for nanoscale patterning definition. The fabricated poly-SiNW device was employed as a biomolecular sensor after adhering the device surface immobilization/modification protocols and used as an early-stage, label-free, and real-time screening of hepatocellular carcinoma. It is later used as a detection device to screen alpha-fetoprotein cancer-related biomarker, DNA fragment of hepatitis B virus, and p16INK4a in squamous cell carcinoma of the cervix.
Our results have exercised the feature of a real-time, label-free, high sensitivity and excellent selectivity biosensor in its settings. These results indicate that the detection of these biomolecules under our direct, label-free, and real-time in an integrated microfluidic channel could be one of the promising state-of-the-art techniques applicable as a biosensor. Thus, could serve as a potential integrated circuit device in clinical applications and as well as a point-of-care device.