title: Ultrasensitive microfluidic solid-phase ELISA using an actuatable microwell-patterned PDMS chip.
abstract: Quantitative detection of low abundance proteins is of significant interest for biological and clinical applications. Here we report an integrated microfluidic solid-phase ELISA platform for rapid and ultrasensitive detection of proteins with a wide dynamic range. Compared to the existing microfluidic devices that perform affinity capture and enzyme-based optical detection in a constant channel volume, the key novelty of our design is two-fold. First, our system integrates a microwell-patterned assay chamber that can be pneumatically actuated to significantly reduce the volume of chemifluorescent reaction, markedly improving the sensitivity and speed of ELISA. Second, monolithic integration of on-chip pumps and the actuatable assay chamber allow programmable fluid delivery and effective mixing for rapid and sensitive immunoassays. Ultrasensitive microfluidic ELISA was demonstrated for insulin-like growth factor 1 receptor (IGF-1R) across at least five orders of magnitude with an extremely low detection limit of 21.8 aM. The microwell-based solid-phase ELISA strategy provides an expandable platform for developing the next-generation microfluidic immunoassay systems that integrate and automate digital and analog measurements to further improve the sensitivity, dynamic ranges, and reproducibility of proteomic analysis.
authors.affiliation: Department of Chemistry, University of Kansas, Lawrence, KS 66045, United States. yongz@ku.edu.
authors.forename: Tanyu
authors.initials: T
authors.lastname: Wang
authors.forename: Mohan
authors.initials: M
authors.lastname: Zhang
authors.forename: Dakota D
authors.initials: DD
authors.lastname: Dreher
authors.forename: Yong
authors.initials: Y
authors.lastname: Zeng
mesh_terms: D015415:Biomarkers / Q000032:analysis; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D017526:Receptor, IGF Type 1 / Q000032:analysis*
chemical_list: D015415:Biomarkers; D004129:Dimethylpolysiloxanes; D017526:Receptor, IGF Type 1