title: On-chip dual detection of cancer biomarkers directly in serum based on self-assembled magnetic bead patterns and quantum dots.
abstract: A sandwich immunoassay method for rapid detection of dual cancer biomarkers in serum on a magnetic field controllable microfluidic chip (MFCM-Chip) was established. A nickel pattern was used to generate high magnetic field gradients to increase the magnetic force on the superparamagnetic beads (SPMBs), which enabled the rapid generation of controllable SPMB patterns in microfluidic channels. The SPMB patterns could keep stable during the fast continuous washing process even at a flow rate of 50 μL/min. This approach demonstrated excellent specificity because the fast continuous washing could remove non-specifically adsorptive contaminants more efficiently than fixed volume batch washing. This approach was used to simultaneously detect carcinoma embryonic antigen (CEA) and α-fetoprotein (AFP) directly in serums. The whole on-chip detection was finished within 40 min, which was much faster than conventional enzyme-linked immunosorbent assay (ELISA) method. High luminescent streptavidin modified QDs (SA-QDs) were used as fluorescence indicators, and the detection limits were 3.5 ng/mL and 3.9 ng/mL for CEA and AFP, respectively. The linear ranges were from 10.0 ng/mL to 800.0 ng/mL. With the high sensitivity, high selectivity and short assay time, this approach could be used for rapid, high throughput detection of cancer biomarkers in clinical trials.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Yu
authors.forename: He-Shun
authors.initials: HS
authors.lastname: Xia
authors.forename: Zuo-Dong
authors.initials: ZD
authors.lastname: Sun
authors.forename: Yi
authors.initials: Y
authors.lastname: Lin
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.forename: Hao
authors.initials: H
authors.lastname: Tang
authors.forename: Dai-Wen
authors.initials: DW
authors.lastname: Pang
authors.forename: Zhi-Ling
authors.initials: ZL
authors.lastname: Zhang
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D015374:Biosensing Techniques / Q000295:instrumentation; D001774:Blood Chemical Analysis / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D018189:Immunomagnetic Separation / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D009369:Neoplasms / Q000097:blood* / Q000175:diagnosis*; D045663:Quantum Dots; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*
chemical_list: D014408:Biomarkers, Tumor