Design and Fabrication of Optical Flow Cell for Multiplex Detection of β-lactamase in Microchannels

Miniaturized quantitative assays offer multiplexing capability in a microfluidic device for high-throughput applications such as antimicrobial resistance (AMR) studies. The detection of these multiple microchannels in a single microfluidic device becomes crucial for point-of-care (POC) testing and clinical diagnostics. This paper showcases an optical flow cell for detection of parallel microchannels in a microfluidic chip. The flow cell operates by measuring the light intensity from the microchannels based on Beer-Lambert law in a linearly moving chip. While this platform could be tailored for a wide variety of applications, here we show the design, fabrication and working principle of the device. β-lactamase, an indicator of bacterial resistance to β-lactam antibiotics, especially in milk, is shown as an example. The flow cell has a small footprint and uses low-powered, low-cost components, which makes it ideally suited for use in portable devices that require multiple sample detection in a single chip.