Optofluidic laser for dual-mode sensitive biomolecular detection with a large dynamic range.
Enzyme-linked immunosorbent assay (ELISA) is a powerful method for biomolecular analysis. The traditional ELISA employing light intensity as the sensing signal often encounters large background arising from non-specific bindings, material autofluorescence and leakage of excitation light, which deteriorates its detection limit and dynamic range. Here we develop the optofluidic laser-based ELISA, where ELISA occurs inside a laser cavity. The laser onset time is used as the sensing signal, which is inversely proportional to the enzyme concentration and hence the analyte concentration inside the cavity. We first elucidate the principle of the optofluidic laser-based ELISA, and then characterize the optofluidic laser performance. Finally, we present the dual-mode detection of interleukin-6 using commercial ELISA kits, where the sensing signals are simultaneously obtained by the traditional and the optofluidic laser-based ELISA, showing a detection limit of 1 fg ml(-1) (38 aM) and a dynamic range of 6 orders of magnitude.
1] Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109, USA [2] Key Laboratory for Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China [3].
Xiang
X
Wu
1] Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109, USA [2].
Maung Kyaw Khaing
MK
Oo
1] Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109, USA [2] Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109, USA.
Karthik
K
Reddy
Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109, USA.
Qiushu
Q
Chen
Department of Electrical Engineering, University of Texas at Arlington, Arlington, Texas 76019, USA.
Yuze
Y
Sun
Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109, USA.
Xudong
X
Fan
D000906:Antibodies / Q000378:metabolism; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation* / Q000379:methods*; D015850:Interleukin-6 / Q000032:analysis; D007834:Lasers; D057230:Limit of Detection
D000906:Antibodies; D015850:Interleukin-6