Biosensing on the CD microfluidic platform with genetically engineered proteins

The current Si/polymeric medical diagnostic sensors that are on the market only feature a one-point calibration system [1]. Such a measurement results in less accurate sensing and more in-factory sensor rejection. The two-point calibration fluidic method introduced here will alleviate some of the shortcomings of such current miniature analytical systems. Our fluidic platform is a disposable, multi-purpose micro analytical laboratory on a compact disc (CD) [2, 3]. This system is based on the centrifugal force, in which fluidic flow can be controlled by the spinning rate of the CD and thus a whole range of fluidic functions including valving, mixing, metering, splitting, and separation can be implemented. Furthermore, optical detection such as absorption and fluorescence can be incorporated into the CD control unit to obtain signals from pre-specified positions on the disc. For such optical detection schemes, it is important that the CD polymer provides no interference (e.g., fluorescence/absorbance background) in the spectral region of the molecular probe employed in the assay. Herein, the spectral characteristics of three prospective CD polymers are also investigated. In addition, studies regarding the compatibility of using these polymers in conjunction with biological reagents were performed.