Design and application of a portable luminometer for bioluminescence detection.

The silicon photomultiplier (SiPM) for low light detection has many advantages when compared to existing photon counting detectors, such as high sensitivity, low cost, robustness, and compact hardware. To facilitate the use of SiPM as a portable, field deployable device, an electrical circuit was designed consisting of an amplifier, comparator, and microcontroller. In addition, a 3D printing was used to create a portable cradle for housing the SiPM. To evaluate its detection ability, a laser experiment and bioluminescent experiments, including Pseudomonas fluorescens M3A detection, E. coli O157:H7 PhiV10nluc lysogen detection, and a luminescence-based detection of E. coli O157:H7 in ground meat using the engineered luminescent-based reporter phage PhiV10nluc, were conducted. In the same experimental setting, our previously developed smartphone-based luminometer called the bioluminescent-based analyte quantitation by smartphone and a conventional photomultiplier tube-based benchtop luminometer were used to compare detection levels and applicability for supporting luminescent phage-based pathogen detection. Results showed that the SiPM provides better performance in terms of time to detection and SNR and could be used as the light detection component of the PhiV10nluc phage-based detection format.