Invited Review Article: Review of centrifugal microfluidic and bio-optical disks

Abstract

Spinning biodisks have advantages that make them attractive for specialized biochip applications. The two main classes of spinning biodisks are microfluidic disks and bio-optical compact disks ͑BioCD͒. Microfluidic biodisks take advantage of noninertial pumping for lab-on-a-chip devices using noninertial valves and switches under centrifugal and Coriolis forces to distribute fluids about the disks. BioCDs use spinning-disk interferometry, under the condition of common-path phase quadrature, to perform interferometric label-free detection of molecular recognition and binding. The optical detection of bound molecules on a disk is facilitated by rapid spinning that enables high-speed repetitive sampling to eliminate 1 / f noise through common-mode rejection of intensity fluctuations and extensive signal averaging. Multiple quadrature classes have been developed, such as microdiffraction, in-line, phase contrast, and holographic adaptive optics. Thin molecular films are detected through the surface dipole density with a surface height sensitivity for the detection of protein spots that is approximately 1 pm. This sensitivity easily resolves a submonolayer of solid-support immobilized antibodies and their antigen targets. Fluorescence and light scattering provide additional optical detection techniques on spinning disks. Immunoassays have been applied to haptoglobin using protein A/G immobilization of antibodies and to prostate specific antigen. Small protein spots enable scalability to many spots per disk for high-throughput and highly multiplexed immonoassays.

Direct Optical Detection in Bioanalytics

“…This company changed its name in 2010 to Perfinity Biosciences Inc. and focused on protein sample preparation [61]. Recent achievements have been reviewed [62] and the detection of prostate-specific antigen in patient sera by a fluorescence-free BioCD protein array is given [63].…”

SERS and Microfluidics

“…The centrifugal microfluidics platform uses rotational forces (radial force, Coreolis force) and acceleration forces in combination with capillary and inertial forces for fluid management in microfluidic networks [15,16]. Microfluidic networks are arranged radial symmetrically on a disc (Figure 8.7).…”

Detection methods for centrifugal microfluidic platforms

“…Several reviews are available, describing realizations and applications of centrifugal microfluidics in general Gorkin et al, 2010;Madou et al, 2006;Nolte, 2009) as well as on methods for handling particles on centrifugal platforms . While most of these reviews focus on methods for liquid handling and control, King and colleagues recently reviewed optical detection methods for lab-on-a-disc systems (King et al, 2014).…”