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This manuscript describes a portable and low cost fluorescence set-up to quantify the concentrations of Ochratoxin A (OTA) in real samples using a developed system. The detection through the set up consist of an ultraviolet light at 365 nm and a CMOS sensor controlled by an executable interface designed in MATLAB, with a time consumed from acquisition to processing to image display of 20 seconds. It is reported that OTA is naturally fluorescent, so it allows the user to get a photograph of the OTA under excitation conditions and process the image in order to predict the concentrations of the sample. To capture and process the image, in an automatically manner, the system was completely based on the Red, Green and Blue (RGB) components. For each concentration of the OTA, the R, G, B coordinates were obtained and plotted to quantify the mycotoxin presented in the sample. The linearity for OTA was obtained in the concentrations range of 5–40 μg/L. Immunoaffinity columns (IAC) and molecular imprinted polymer columns (MIP) were compared. The maximum recovery of 107.76% was recorded for 2 μg/L of OTA using IAC in beer samples. The obtained results were cross validated using chromatographic method HPLC. The developed setup is easy to use, economical and portable.

The development of a fully automated flow electrochemical aptasensor based on the use of a selective capture aptamer and modified magnetic beads (MBs) is reported. The developed flow-based aptasensor is demonstrated under continuous/stopped flow conditions for the detection of ochratoxin A (OTA) employing direct and indirect competitive strategies. In the direct format, biotin labeled and free OTA competed to bind with immobilized aptamer onto the surface of a screen printed carbon electrode (SPCE) placed in a flow cell. In the indirect assay, immobilized OTA and free OTA in solution competed to bind with aptamer in solution. The current response obtained from the conversion of the substrate 1-naphtyl phosphate by ALP decreased proportionally to the concentration of OTA in the sample. A lower limit of detection (0.05 μg/L) was obtained with the indirect flow-based aptasensor. Finally, the flow-based aptasensor was validated with real beer samples, and the good recovery values demonstrated the efficiency of the competitive aptasensor.