Label-free, multiplexed detection of bacterial tmRNA using silicon photonic microring resonators

A label-free biosensing method for the sensitive detection and identification of bacterial transfer-messenger RNA (tmRNA) is presented employing arrays of silicon photonic microring resonators. Species specific tmRNA molecules are targeted by complementary DNA capture probes that are covalently attached to the sensor surface. Specific hybridization is monitored in near real-time by observing the resonance wavelength shift of each individual microring. The sensitivity of the biosensing platform allowed for detection down to 53 fmol of Streptococcus pneumoniae tmRNA, equivalent to approximately 3.16×107 CFU of bacteria. The simplicity and scalability of this biosensing approach makes it a promising tool for the rapid identification of different bacteria via tmRNA profiling.

► tmRNAs are promising markers for distinguishing between pathogenic bacterial species.
► Quantitation of multiple tmRNAs is demonstrated using a silicon photonic detection platform.
► Scalable tmRNA detection is needed for biodefense, food monitoring, and health care, among others.