Active and Ultrasensitive Chemical and Biosensing through Optothermally Generated Microbubble
In this work a cost-effective, label free and ultra-sensitive chemical and biosensing method has been demonstrated for active sensing of analytes. Development of an affordable and ultrasensitive sensing methods is critical. The most challenge in this area is the efficient management of detection time and sensitivity of sensor. Most of the sensing systems reported in the literature usually apply a passive sensing method in which binding of analytes occurs after waiting for the analytes to freely diffuse towards the sensor. Due to this free diffusion, analytes usually take very longer times to diffuse on the sensor, and therefore becomes a diffusion-limited method. In order to overcome this diffusion limit, active sensing method can be used in which analytes are forced towards the sensor for active diffusion. In this work, a cost-effective and ultrasensitive chemical and biosensing platform has been developed under ambient condition to demonstrate an active sensing method. This method works based on an optothermally generated microbubble (OGMB); a micron-sized bubble which is generated on a liquid-solid interface through laser heating of metallic nanoparticles solution. Due to a strong convective flow induced by OGMB, nanoparticles are attracted towards OGMB and rapidly deposited on the surface of a substrate to fabricate a nanogap-rich structure. This structure forms many nanogaps which are ideal for surface enhance Raman scattering (SERS) enhancement due to the plasmonic resonance. Liquid solutions containing an analyte is attached on nanogap-rich structure to develop the chemical and biosensing platform. In addition, OGMB is used to locally concentrate anaylytes around nanogap-rich structure for active sensing. Active sensing can improve the detection limit of analytes by one order of magnitude compared to passive sensing. This active sensing method can overcome the diffusion limit of conventional sensing methods and paves a new way for advanced chemical and bio-sensing application.
Primary Advisor's Department
Electro-Optics and Photonics
Stander Symposium project, School of Engineering
United Nations Sustainable Development Goals
Good Health and Well-Being
"Active and Ultrasensitive Chemical and Biosensing through Optothermally Generated Microbubble" (2020). Stander Symposium Projects. 1816.