Light-addressable potentiometric penicillin image sensor using the self-assembled monolayer immobilizing method

In this study, the LAPSs (light addressable potentiometric sensors) which have devices of Si/sub 3/N/sub 4//SiO/sub 2//Si, Ta/sub 2/O/sub 5//SiO/sub 2//Si structure were fabricated. Also, it was investigated the response characteristics to penicillin concentration and detected the 2D images of 128 /spl times/ 128 pixels. The penicillinase was immobilized on the devices to hydrolyze the penicillin using self-assembled monolayer (SAM) method. The measuring system was simplified by using Lab VIEW software. The result of the enzyme reaction, the sensitivity of the sensor which has Si/sub 3/N/sub 4/ surfaces was 60 mV/decade and Ta/sub 2/O/sub 5/ surfaces was 74 mV/decade in the range of 0.1 mM /spl sim/ 10 mM of the penicillin concentration. Image detecting time by an enzyme reaction between penicillin and penicillinase took about 10 minutes at 128 /spl times/ 128 pixels in 1 /spl times/ 1 cm sensing area.