Based on the working principle of the light addressable potentiometric sensors (LAPS) and the diffusion theory about the photo-carrier in a silicon chip

a design of the new LAPS structure was advanced newly

with the measuring cell by front illumination

the quickset of LAPS array chip and the silicon tips array.The photocurrent signal of the new LAPS is five times photocurrent of the LAPS by back illumination.When this sensor was used for determining pH value in buffer solution of pH 4.00

pH 6.86

pH 9.18

the correlation coefficient is 0.9999

the response sensitivity is 50.1mV/pH

the standard deviation and variation coefficient for 4 times performances response to buffer solution of pH 9.18 were found to be 0.57mV and 0.048% respectively.Finally

this paper analyzed and discussed the testing method of three electrodes

feature of the new LAPS and the infections of conductance of waiting testing electrolyte on photocurrent.