fig3

Figure 3. Representative optical biosensor configurations for biochemical sensing. (A) Schematic of a stretchable optical strain sensor based on LSPR for human-activity monitoring. Reproduced with permission^[84]. Copyright 2019, American Chemical Society; (B) Plasmonic fluorescence biosensor based on PCR amplification for rapid and sensitive biomolecular analysis. Reproduced with permission^[85]. Copyright 2021, Royal Society of Chemistry; (C) Schematic illustration of a magnetic nanochain-integrated microfluidic biochip platform for multiplexed biosensing. Reproduced with permission^[87]. Copyright 2018, Springer; (D) Ultra-compact dual-channel integrated CO₂ infrared gas sensor based on on-chip NDIR technology. Reproduced with permission^[88]. Copyright 2024, Springer. GNP: Gold nanoparticle; PDMS: polydimethylsiloxane; IR: infrared; LED: light-emitting diode; PPT: plasmonic photothermal; PCR: polymerase chain reaction; PMN: plasmonic magnetic nanoparticle; SERS: surface-enhanced Raman scattering; MEMS: PCB: printed circuit board; LSPR: localized surface plasmon resonance; NDIR: non-dispersive infrared.