In situSynthesis of Oligonucleotide and Detection of Gold‐label‐silver‐stain on PTFE Slices

Abstract Poly(tetrafluoroethylene) (PTFE) was treated with plasma in a mixture of nitrogen and hydrogen (1:2 in volume). X‐ray photoelectron spectroscopy (XPS) demonstrated the success of amino group grafting. The as‐treated PTFE slices were successively applied to the in situ synthesis of oligonucleotides. With the detection of gold‐label‐silver‐stain, the hybridization signals were recorded with a gel document and analysis system. A target DNA concentration as low as 10 pmol/L could be detected. The complementary and mismatched sequences were distinguished clearly, and the ratio of background‐subtracted gray scale values for perfect match:1 base mismatch:2 base mismatch:3 base mismatch was 72:44.4:22.5:11.4. The sensitivity of in situ synthesis system was 1 order of magnitude higher than that of spotting system, and the signal of the former was about 1.5 times stronger than that of the latter under the same target DNA concentration. These plasma modified PTFE slices might open novel prospects for the in situ synthesis of DNA micro‐arrays.