[Nano Letters] AC Electroosmosis-Enhanced Nanoplasmofluidic Detection of Ultralow-Concentration Cyto
Label-free, nanoparticle-based plasmonic optical biosensing, combined with device miniaturization and microarray integration, has emerged as a promising approach for rapid, multiplexed biomolecular analysis. However, limited sensitivity prevents the wide use of such integrated label-free nanoplasmonic biosensors in clinical and life science applications where low-abundance biomolecule detection is needed. Here, we present a nanoplasmofluidic device integrated with microelectrodes for rapid, label-free analysis of a low-abundance cell signaling protein, detected by AC electroosmosis-enhanced localized surface plasmon resonance (ACE-LSPR) biofunctional nanoparticle imaging. The ACE-LSPR device is constructed using both bottom-up and top-down sensor fabrication methods, allowing the seamless integration of antibody-conjugated gold nanorod (AuNR) biosensor arrays with microelectrodes on the same microfluidic platform. Applying an AC voltage to microelectrodes while scanning the scattering light intensity variation of the AuNR biosensors results in significantly enhanced biosensing performance. The AC electroosmosis (ACEO) based enhancement of the biosensor performance enables rapid (5–15 min) quantification of IL-1β, a pro-inflammatory cytokine biomarker, with a sensitivity down to 158.5 fg/mL (9.1 fM) for spiked samples in PBS and 1 pg/mL (58 fM) for diluted human serum. Together with the optimized detection sensitivity and speed, our study presents the first critical step toward the application of nanoplasmonic biosensing technology to immune status monitoring guided by low-abundance cytokine measurement.
Yujing Song†, Pengyu Chen‡, Meng Ting Chung†, Robert Nidetz†, Younggeun Park†, Zhenhui Liu§, Walker McHugh⊥, Timothy T. Cornell⊥, Jianping Fu†∥# , and Katsuo Kurabayashi*†∇ †Department of Mechanical Engineering, ⊥Department of Pediatrics and Communicable Diseases, ∥Department of Biomedical Engineering, ∇Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, United States ‡ Materials Research and Education Center, Auburn University, Auburn, Alabama 36849, United States § Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, People’s Republic of China # Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States Nano Lett., Article ASAP DOI: 10.1021/acs.nanolett.6b05313 Publication Date (Web): March 15, 2017 Copyright © 2017 American Chemical Society *E-mail: email@example.com.