Biosensor component converting biological signal to electrical signal is:
Biosensor architecture integrates three functional modules working in concert: bioreceptor such as enzyme, antibody, aptamer or whole cell conferring molecular recognition specificity, transducer that converts biorecognition event into quantifiable physical signal, and signal processing display unit amplifying and presenting output. Transducer role remains pivotal because biochemical interactions like enzyme-substrate turnover producing protons or hydrogen peroxide, antibody-antigen binding causing mass change, or DNA hybridization changing charge do not inherently generate electrical signals compatible with electronics. Depending on design, electrochemical transducer produces current, potential or impedance change, optical transducer translates fluorescence intensity, surface plasmon resonance shift or bioluminescence, thermal transducer measures enthalpy via thermistor, and piezoelectric quartz crystal microbalance measures mass change to frequency shift in nanograms. Materials include screen-printed carbon electrodes, field-effect transistors functionalized with gold nanoparticles, or optical fibers. Without efficient transduction, selective binding remains invisible. Metrics like sensitivity, limit of detection and response time under 30 seconds directly reflect transducer efficiency and coupling chemistry at bio-electronic interface.
Ref: Tuan Vo-Dinh et al. Biosensors and Bioelectronics Handbook; Alberts Cell Ch signal transduction devices; Nature Biotech 2020 review.