Estimation of Beta-amyloid Quantity Using Photo-Sensitive Field Effect Transistor Integrated with a Selectively Transmissible Optical Filter

The intra/extracellular beta-amyloid (Aβ) of neuron has been known as the most representative hallmark of Alzheimer´s disease (AD). Recently, the clinical diagnosis of AD has been significantly issued with early detection of Aβ. For further accurate quantification of Aβ compared to current techniques, we suggest a new technical concept that enables the evaluation of as small as a few femtomolar Aβ peptide by using photo-sensitive field-effect transistor (p-FET) coated with selectively transmissible optical filter for a particular range of wavelengths of excitation beam. The photo-current generated by p-FET with arsenic trisulfide (As₂S₃) filter is as much apparent as about 76 nA for a small amount of Aβ-conjugated fluorescent particles. This result indicates that even with slightly small amount of Aβ peptides the As₂S₃ coated p-FET is applicable to recognizing optically tenuous fluorescence.