Lab-on-Chip platform and protocol for rapid foodborne pathogen detection comprising on-chip cell capture, lysis, DNA amplification and surface-acoustic-wave detection

Abstract

We present an integrated, compact, lab on a chip (LoC) platform and protocol for rapid pathogen analysis in food samples. The proposed LoC is based on an oxygen plasma nanotextured polymeric chip combining in one microfluidic chamber bacteria immunoaffinity capturing on the chip surface, chemical lysis and DNA isothermal amplification, followed by label-free detection with a Surface Acoustic Wave (SAW) biosensor. The proposed operation protocol includes: 1) a short (3 h) off-chip pre-culturing step, starting from 1 to 5 CFUs in only 25 ml of spiked fresh or pasteurized milk, followed by a brief centrifugation step for concentration of the 25 ml down to 100 μl, and, 2) injection of the preconcentrated sample on chip for automated bacterial capture, lysis, DNA amplification and acoustic detection. The sample-to-answer analysis time was less than 4.5 h, which is at least 5-times faster compared to conventional methods. Label-free detection of four different bacteria Salmonella, B. cereus, Listeria and E. coli in milk is demonstrated with minimal off chip handling and record fast analysis time.