Channel-resolved multianalyte immunosensing system for flow-through chemiluminescent detection of alpha-fetoprotein and carcinoembryonic antigen.

A novel flow-through immunosensing system for chemiluminescent (CL) multianalyte immunoassay was designed based on channel-resolved technique. Using alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as model analytes, two polyethersulfone membranes modified with the corresponding capture antibodies were set in two channels of a flow cell, and then two mixtures of the sample and corresponding alkaline phosphatase labeled antibodies were introduced into the channels for on-line incubation, respectively. Upon injection of CL substrate the catalyzed CL signals from the two channels were sequentially collected with the aid of an optical shutter for CL detection of two analytes. The antibodies immobilized membranes could be regenerated for reuse. Under optimal conditions AFP and CEA could be assayed in the ranges of 5.0-150 and 0.50-80 ng/ml with detection limits of 1.5 and 0.25 ng/ml, respectively. The assay results of clinical serum samples with the proposed system were in acceptable agreement with those with the reference method in single-analyte test mode. This novel immunosensing system based on the designed channel-resolved technique provided an automated, reusable, simple, sensitive and low-cost approach for multianalyte immunoassay without using of expensive array detector.