Field-deployable whole-cell bioluminescent biosensors: so near and yet so far.

The use of smart supports and bioinspired materials to confine living cells and use them for field-deployable biosensors has recently attracted much attention. In particular, bioluminescent whole-cell biosensors designed to respond to different analytes or classes of analyte have been successfully implemented in portable and cost-effective analytical devices. Significant advances in detection technology, biomaterial science, and genetic engineering of cells have recently been reported. Now the challenge is to move from benchtop traditional cell-based assays to portable biosensing devices. Improvement of the analytical performance of these biosensors depends on the availability of optimized bioluminescent reporters, and promising approaches that go beyond reporter gene technology are emerging. To enable handling of cells as ready-to-use reagents, nature-inspired strategies have been used, with the objective of keeping cells in a dormant state until use. Several issues must still be investigated, for example long-term viability of cells, the possibility of performing real-time analysis, and multiplexing capability.