Porous Silicon as a Carrier of Sensing Materials in Sensors

<正>Novel potassium ion selective electrodes （K+ISEs） and cDNA array sensors based on porous silicon （PS） have been developed.The calibration curve for the K+ISEs is linear within a wide range of pK=2.0～6.0 with the slope of 56 mV per decade,which is near Nernst response.The response time and detection limit are within 31 s and 0.5μmol/L,respectively.The selective coefficient for Na+ is-3.8,satisfies the requirement for the assay of blood potassium.The response variation is within 2 mV during 2 months.The binding capacity,the dynamic range and the detection limit of the DNA sensors were improved by replacing glass slide with PS substrates.The cDNA array sensors can bear 80℃of high temperature,75% of humidity,3.6 kLx of irradiation and keep stable within 10 days when they are exposed in air.Good performances of the K+ISE and the cDNA array sensor are attributed to the large internal surface area and the easily modified microstructure of PS.