A facile method toward potentially next-generation bacteria detectors using polymer/MWCNT/Au nanocomposite films: a possibility to detecting ability through the shift in resonance frequency

The global market demands for new disposable wireless sensors for food, clinical, tissue, and drug industries in the near future. Gelatin-based multi-layer films were successfully prepared using a room temperature solution casting method. Anticipating future developments, we have looked at the potential applications of cost-effective passive RFID tags in the detection of bacteria (here trypsin was used for biosensing tests) in body fluids, foods, medicines, and much more. This paper is concerned with the measurement of the dielectric constant of materials remotely by using the frequency shift of RFID tags, in the first step. In continue, we establish a setup along with a novel multi-layer structure of gelatin films determining whether there exists any bacterium in a biological fluid or not, by using a physical approach. For this, penetration of bacterium through gelatin multi-layer films causes the RFID tags to be exposed to the biological fluid changing the dielectric constant, detected as a frequency shift. Samples were characterized utilizing FTIR, XRD, TGA, FESEM, tensile, and VNA analyzes. Our proposed wireless biomimetic sensor is able to detect trypsin within a few minutes. The immediate application of our designed biosensor is for the elderly and infants diapers, but further applications in biomedicine, biomedical engineering, food industry, and things like that can be anticipated. (paper)