Fig. 3.

All-liquid microreactors. a–c Schematic of the anchoring of cationic molecules (a), enzymes (b), and nanocrystals (c) to the anionic NPS film lining the microchannels. d, e 3D reconstitution of confocal images of methylene blue (d) and LRSC-labeled HRP (e) to determine the adhesion of cationic species to the NPS wall of the microchannel. Scale bars, 100 µm. f In-situ AFM image of the NPS film immobilized with CTAB-coated Pt nanocrystals at the water−silicone oil interface. Scale bar, 100 nm. g, h Oxidation of TMB (g) and 4-AAP/phenol (h) substrates catalyzed by immobilized HRP in the channels, which generate products with distinctive colors under flow. Scale bars, 5 mm. NPS nanoparticle−polymer surfactant, LRSC lissamine rhodamine B sulfonyl chloride, HRP Horseradish peroxidase, TMB 3,3′,5,5′-tetramethylbenzidine, 4-AAP 4-aminoantipyrine