Polyacrylamid/Silver Composite Particles Produced via Microfluidic Photopolymerization for Single Particle-Based SERS Microsensorics

A micro-continuous-flow process was applied for the preparation of swellable polyacrylamide particles incorporating silver nanoparticles. These sensor particles are formed from a mixture of a colloidal solution of silver nanoparticles and monomer by a droplet-based procedure with in situ photoinitiation of polymerization and a subsequent silver enforcement in batch. The obtained polymer composite particles show a strong SEAS effect. Characteristic Raman signals of aqueous solutions of adenine could be detected down to 0.1 mu M by the use of single sensor particles. The chosen example demonstrates that the composite particles are suitable for quantitative microanalytical procedures with a high dynamic range (3 orders of magnitude for adenine).