Recent advances in environmental and clinical analysis using microring resonator-based sensors.

Progress in the development of biosensors has dramatically improved analytical techniques. Biosensors have advantages over more conventional analytical techniques arising from attributes such as straightforward analyses, higher throughput, miniaturization, smaller sample input, and lower cost. Microring optical resonators have emerged in the area of optical sensors as an exceptional choice due to their sensitivity, ease of fabrication, multiplexity capability and label-free detection. In this paper, the sensing principle of these sensors is described. In addition, we summarize and highlight their most recent and relevant applications in environmental and clinical detection analysis.

Multiplexed microRNA Expression Profiling by Combined Asymmetric PCR and Label-Free Detection using Silicon Photonic Sensor Arrays.

Analysis methods based upon the quantitative, real-time polymerase chain reaction are extremely powerful; however, they face intrinsic limitations in terms of target multiplexing. In contrast, silicon photonic microring resonators represent a modularly multiplexable sensor array technology that is well-suited to the analysis of targeted biomarker panels. In this manuscript we employ an asymmetric polymerase chain reaction approach to selectively amplify copies of cDNAs generated from targeted miRNAs before multiplexed, label-free quantitation through hybridization to microring resonator arrays pre-functionalized with capture sequences. This method, which shows applicability to low input amounts and a large dynamic range, was demonstrated for the simultaneous detection of eight microRNA targets from twenty primary brain tumor samples with expression profiles in good agreement with literature precedent.

Combining asymmetric PCR-based enzymatic amplification with silicon photonic microring resonators for the detection of lncRNAs from low input human RNA samples.

A method for quantifying biologically relevant long-non-coding RNAs by combining nucleic acid amplification via asymmetric polymerase chain reaction (PCR) with label-free PCR product detection using silicon photonic microring resonator arrays is described. This approach eliminates the need for fluorophores, which presents a limit for spectral multiplexing in conventional qPCR methods, and rather offers potential for much higher levels of plexity by spatially arraying capture probes. Here, we demonstrate the potential of this technique to detect two differentially expressed lncRNA transcripts and an internal control mRNA transcript in different commercial human tissue specimens, as well as in a glioblastoma cell line using only nanogram input amounts of total RNA. The obtained results were validated using single-plex RT-qPCR and found to be in good agreement, demonstrating the potential of this technique for lncRNA quantification applications.