Performance and flow dynamics studies of polymeric optofluidic sers sensors

We present a polymer-based optofluidic surface enhanced Raman scattering chip for biomolecule detection, serving as a disposable sensorchoice with cost-effective production. The SERS substrate is fabricated by using industrial roll-to-roll UV-nanoimprinting equipment andintegrated with adhesive-based polymeric microfluidics. The functioning of the SERS detection on-chip is confirmed and the effect of thepolymer lid on the obtainable Raman spectra is analysed. Rhodamine 6G is used as a model analyte to demonstrate continuous flowmeasurements on a planar SERS substrate in a microchannel. The relation between the temporal response of the sensors and sample flowdynamics is studied with varied flow velocities, using SERS and fluorescence detection. The response time of the surface-dependent SERSsignal is longer than the response time of the fluorescence signal of the bulk flow. This observation revealed the effect of convection on thetemporal SERS responses at 25 μl/min to 1000 μl/min flow velocities. The diffusion of analyte molecules from the bulk concentration intothe sensing surface induces about a 40-second lag time in the SERS detection. This lag time, and its rising trend with slower flow velocities, has to be taken into account in future trials of the optofluidic SERS sensor, with active analyte binding on the sensing surface

Remote diagnostics and monitoring using microwave technique:improving healthcare in rural areas and in exceptional situations

Abstract Interests towards wireless portable medical diagnostics and monitoring systems, which could be used outside hospital e.g. during pandemic or catastrophic situations, have increased recently. Additionally, portable monitoring solutions could partially address widely recognized challenges related to healthcare equality in rural areas. Microwave based sensing has recently been recognized as emerging technology for portable medical monitoring and diagnostics devices since they may enable development of safe, reliable, and low-cost solutions for future’s telemedicine. The aim of this paper is to present the basic idea of microwave -based medical monitoring and discuss its possibilities, advantages, and challenges. In particular, we show that microwaves could be exploited in three pre-diagnostics applications: 1) Detection of abnormalities in the brain with a helmet type of monitoring device, 2) Detection of breast cancer with a self-monitoring vest, 3) Detection of blood clots in leg with an antenna band. The technique is based on detecting differences in radio channel responses caused by the abnormalities having different dielectric properties than the surrounding tissues. Our results of realistic simulations and experimental measurements show that even small-sized abnormalities, e.g. tumors, can change channel characteristics in detectable level