Detection of uncharged or feebly charged small molecules by field-effect transistor biosensors

► A new technique for the detection of uncharged or feebly charged small molecules (<400 Da) using Si field-effect transistor (FET) biosensors are described. ► FET signal are signal-enhanced by gold nanoparticle (NP) charges under dry measurement conditions. ► The signal is 100 times more enhanced than the use of the existing solution FET biosensing techniques. ► This method enables the FET biosensor to quantitatively detect small mycotoxin molecules, regardless of the ionic strengths, isoelectric points (pI), or pHs of the measured sample solutions.