Nano-Porous Silicon Based Immune Biosensor for ...

The efficiency of the nano-porous silicon (sNPS) application as the transducer in the immune biosensor designed for the level control of mycotoxins among environmental objects was studied. T2 and patulin were chosen as model objects. Boron doped single-crystal silicon square wafers with the resistivity of 1 Ohmcm, area of 100 cm2 and thickness of 0.3 m was used. The surface was prepared by stain etching in 4HF:1HNO3:4H2O solution. sNPS surface is regularly covered with nano-scale hills up to 20 nm high. The registration of the specific signal was made on the basis of changes of chemiluminescence (ChL) or photocurrent of the sNPS. The biosensor sensitivity for both variants was 10-20 ng/ml at the total time of analysis lasting for 40 min. This time may be a sharp decline if specific antibodies (Ab) will be preliminary immobilized. It was concluded that the proposed immune biosensor was effective if the analysis will be fulfilled in screening regime. For the verification of the results or for more accurately determination of mycotoxin level, it is necessary to find way for increasing sensitivity, or to apply another analytical approach.