Microbioreactor with Photodiode Detection for Monitoring Intracellular GFPUV Expression in E. coli

A prototype membrane aerated polydimethylsiloxane (PDMS) microbioreactor integrated with a photodiode detector was developed for monitoring intracellular green fluorescent protein ultraviolet (GFPUV) expression in Escherichia coli. The developed system is compact, simple and inexpensive and ideal for economical on chip detection of fluorophores in aqueous solution and intracellular GFPUV expression. The detection limit for cell free GFPUV was found to be 4.8 x 10-8 M. Intracellular GFPUV expression in E. coli cells was monitored for 12 h and the lowest detectable signal was recorded from a cell concentration of 2.7 x 107cells/mL with signal to noise ratio (SNR) value of 3. The performance of the photodiode detector was benchmarked with a CCD spectrophotometer and results showed favorable comparison. A miniaturized microbioreactor for monitoring intracellular dynamics in real time is demonstrated.