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Chromatography is a robust purification technique, but requires time-consuming optimization on a case-by-case basis, particularly for monoclonal antibodies (mAbs). This work presents a novel microfluidic platform that significantly speeds up the optimization process and reduces the amount of reagent needed. Binding kinetics for a fluorescent conjugate mAb-Alexa 430 were measured in real time at resin level by integration of the microfluidic chip with 200×200 μm a-Si:H photodiodes on glass substrates aligned with micro-columns. Screening studies were performed using reduced amounts of reagents (∼50 μL), mAb molecules (∼2.5 μL) and resin (∼70 nL) in a rapid (∼2 min/condition) and simple manner.

Food safety can be seriously compromised by the presence of mycotoxins. Their detection becomes increasingly relevant as they are subject to strict regulations in the European Union. To cope with this demand, a novel device with manually operated magnetic valves was developed and applied in a direct competitive immunoassay with multiplexed chemiluminescence detection of ochratoxin A, aflatoxin B1 and deoxynivalenol. The optical detection of chemiluminescence from the enzymatically labelled antibodies is performed with a microfabricated array of 25 μm x 25 μm hydrogenated amorphous silicon (a-Si:H) photoconductors. This strategy provides a simple multiplexing device for mycotoxin screening on the field.

The assurance of strict food safety standards is a major challenge in modern society. Mycotoxins, in particular, are produced by fungi during production, storage or transport, posing serious health concerns to humans and animals. Aiming at developing a point-of-use tool for the rapid detection of mycotoxins at the required regulatory levels, we report a microfluidic ultrafast and single-step fluorescence-based immunoassay, using minimal amounts of reagents. This assay was integrated with 200×200 μm thin-film a-Si:H photodiodes towards a compact detection system. Aflatoxin B1 was detected at 1 ng/mL after 2 min assay time, among the fastest reported in the literature.