Label-free quantitation of a cancer biomarker in complex media using silicon photonic microring resonators.
Recent advances in label-free biosensing techniques have shown the potential to simplify clinical analyses. With this motivation in mind, this paper demonstrates for the first time the use of silicon-on-insulator microring optical resonator arrays for the robust and label-free detection of a clinically important protein biomarker in undiluted serum, using carcinoembryonic antigen (CEA) as the test case. We utilize an initial-slope-based quantitation method to sensitively detect CEA at clinically relevant levels and to determine the CEA concentrations of unknown samples in both buffer and undiluted fetal bovine serum. Comparison with a commercial enzyme-linked immunosorbent assay (ELISA) kit reveals that the label-free microring sensor platform has a comparable limit of detection (2 ng/mL) and superior accuracy in the measurement of CEA concentration across a 3 order of magnitude dynamic range. Notably, we report the lowest limit of detection to date for a microring resonator sensor applied to a clinically relevant cancer biomarker. Although this report describes the robust biosensing capabilities of silicon photonic microring resonator arrays for a single parameter assay, future work will focus on utilizing the platform for highly multiplexed, label-free bioanalysis.
Washburn
Adam L
AL
Department of Chemistry, Institute for Genomic Biology, and Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.
Gunn
L Cary
LC
Bailey
Ryan C
RC
D000906:Antibodies / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D006801:Humans; D055617:Micro-Electrical-Mechanical Systems; D009369:Neoplasms / Q000175:diagnosis*; D055095:Optics and Photonics / Q000379:methods; D012825:Silicon / Q000737:chemistry
D000906:Antibodies; D002272:Carcinoembryonic Antigen; D012825:Silicon