Figure 5: Optoelectrofluidic tools for biological and chemical applications. (a) Active surface-enhanced Raman scattering (SERS) substrate for in situ detection of molecules in a specific area at a specific time of interest (Hwang et al. [66]—reproduced by permission of The Royal Society of Chemistry). (b) Measurement of molecular diffusion coefficient by analyzing recovery rate after optoelectrofluidic molecular depletion from the illuminated area at a low AC frequency condition (adapted with permission from Hwang and Park [67], Copyright 2009 American Chemical Society). (c) Sandwich immunoassays driven by a dynamic image pattern and optoelectrofluidic mechanisms for detection of human tumor marker using SERS probe nanoparticles (adapted with permission from Hwang et al. [76], Copyright 2010 American Chemical Society).