Highly sensitive fluorescence detection system for microfluidic lab-on-a-chip

Abstract

We demonstrate a compact, low cost and practical fluorescence detection system for lab-on-a-chip applications. The system comprises a commercially available InGaN light emitting diode (501 nm) as light source, an organic or silicon photodiode detector, absorptive dye coated colour filters and linear and reflective polarisers. An injection moulded polystyrene microfluidic chip is used as the platform for fluorescence immunoassays for cardiac markers myoglobin and CK-MB. The optical limit of detection (LOD) is measured using a TransFluoSphere® suspension at 5.6 × 10(4) beads µl(-1) which can be equated to ∼3 nM fluorescein equivalent concentration. The LOD for the human plasma immunoassays is measured as 1.5 ng ml(-1) for both myoglobin and CK-MB.

Fibre coupled micro-light emitting diode array light source with integrated band-pass filter for fluorescence detection in miniaturised analytical systems

“…and their assembly into a functioning optical system is the limiting factor when creating a miniaturized CE-LIF design either LIF or LED-IF. As LEDs have wide spatial light distribution, focusing optics is usually required for optimal sensitivity of LED-IF detection [45,53,54]. Optical fibres directly coupled to LEDs (pigtailed LEDs) [47,55,56] are a very popular alternative in creating a spatially directed LED light source.…”

Recent advances in microfluidic technologies for biochemistry and molecular biology

“…In this study, multiple DNA-encoded antibody barcode arrays are patterned within the channel for protein measurement. Finally, as a first step towards disposable, stand-alone diagnostic devices for a range of fluorescence-based microfluidic assays, deMello and co-workers have pioneered the use of a polymer LEDs and photodiodes as excitation sources and photon detectors (73)(74)(75)(76). http://bmbreports.org Such systems provide excellent detection limits and sensitivities whilst having small-footprints and being extremely cheap to fabricate and integrate with microfluidic systems (75).…”

Automated, Miniaturized, and Integrated Quality Control-on-Chip (QC-on-a-Chip) for Cell-Based Cancer Therapy Applications

“…Furthermore, the latest progress in OFET development points at the potential toward the fabrication of a low-cost, printable, flexible, highly sensitive, and selective detection platform for the integration into LoC analysis and sensor repertoire (Torsi et al, 2002;Someya et al, 2010). Another recent advancement includes the application of solution-processed fully spraycoated organic photodiodes (OPDs) (Figure 3E) (Tedde et al, 2009) for cell analysis, which allows the integration of disposable fluorescence and chemiluminescence sensors in cartridge-based analysis systems (Hofmann et al, 2005;Wang and Amatatongchai, 2009;Ryu et al, 2011). To study the electrical properties of mammalian cells, a variety of electroanalytical methods, such as voltammetry, potentiometry, and impedance spectroscopy, are available to provide information of cell viability, proliferation, and morphology changes.…”