Miniaturized bioluminescent whole-cell sensor systems

Relying on the biological responses and activity of living cells, bioluminescent whole-cell biosensors generate an optical signal in response to the presence of target compounds. The miniaturization of low-light detectors and their integration with microfluidics have allowed the realization of portable devices for sensitive imaging and quantification of these signals. This review thus focuses on bioluminescence-based whole-cell biosensors, integrated with handheld optical detectors, with an emphasis on the use of the low-light imaging capability of modern smartphones. We highlight state-of-the-art miniaturization techniques applied to the incorporation of living cells into diverse hardware platforms, and to the sensitive recording of the biologically generated photons. The integration of sample introduction, host-cell activity maintenance, luminescence acquisition, data processing/presentation, and portability are also discussed.