Development of a multichannel microfluidic analysis system employing affinity capillary electrophoresis for immunoassay

Cheng, SB Skinner, CD Taylor, J Attiya, S Lee, WE Picelli, G Harrison, DJ

Sb. Cheng et al., Development of a multichannel microfluidic analysis system employing affinity capillary electrophoresis for immunoassay, ANALYT CHEM, 73(7), 2001, pp. 1472-1479

28

INGLESE

Article

Chemistry & Analysis","Spectroscopy /Instrumentation/Analytical Sciences

ANALYTICAL CHEMISTRY

0003-2700 → ACNP

73

7

2001

1472 - 1479

ISI

0003-2700(20010401)73:7<1472:DOAMMA>2.0.ZU;2-4

A six-channel microfluidic immunoassay device with a scanned fluorescence d etection system is described. Six independent mixing, reaction, and separat ion manifolds are integrated within one microfluidic wafer, along with two optical alignment channels. The manifolds are operated simultaneously and d ata are acquired using a singlepoint fluorescence detector with a galvano-s canner to step between separation channels. A detection limit of 30 pM was obtained for fluorescein with the scanning detector, using a 7.1-Hz samplin g rate for each of the reaction manifolds and alignment channels (57-Hz ove rall sampling rate). Simultaneous direct immunoassays for ovalbumin and for anti-estradiol were performed within the microfluidic device. Mixing, reac tion, and separation could be performed within 60 s in all cases and within 30 s under optimized conditions. Simultaneous calibration and analysis cou ld be performed with calibrant in several manifolds and sample in the other manifolds, allowing a complete immunoassay to be run within 30 s, Careful chip conditioning with methanol, water, and 0.1 M NaOH resulted in peak hei ght RSD values of 3-8% (N = 5 or 6), allowing for cross-channel calibration , The limit of detection (LOD) for an anti-estradial assay obtained in any single channel was 4.3 nM, The LOD for the cross-channel calibration was 6. 4 nM. Factors influencing chip and detection system design and performance are discussed in detail.