Front Cover: Diamond electrolyte solution gate FETs for DNA and protein sensors using DNA/RNA aptamers (Phys. Status Solidi A 9/2011)

For DNA and protein detection, Kawarada and Ruslinda (see pp. 2005–2016) have analyzed DNA/RNA immobilized transistortype biosensors based on diamond surfaces, where several types of atomic or molecule termination have been realized. Amine termination and carboxyl termination substantial for biomolecule immobilization can be formed directly on diamond surface. The immobilization of DNA/RNA is realized within 1-2 nm from the surface. Due to high areal capacitance, the surface charge change caused by hybridization of DNA/RNA and protein binding to the DNA/RNA aptamer can be effi ciently detected. The charge of surface termination such as NH3+ , O−, COO− has some effect on the suppression of non-specifi c binding. As a result, biomolecule detection, such as one-base mismatch of DNA or protein detection, unaffected by non-specifi c binding can be realized.