Research On The Photosensitive System For The Light-directed Synthesis Of Peptide Nucleic Acid Chip

ABSTRACT:Improving the photodeprotection efficiency of photosensitive groups is a crucial procedure in the preparation of biochip via photodeprotection technique. Under a certain low-light-intensity condition, one of the possible approaches is to use photosensitizer.Applying9H-thioxanthen-9-one (TX) as sensitizer and utilizing its triplet state energy for the photodeprotection in the synthesis of DNA chip, in which protecting groups protected hydroxyl, can improve the deprotection rate to a certain extent. However, the foregoing sensitizer didn’t provide a satisfactory result in the synthesis of peptide nucleic acid chip. In this paper, pyrene and its derivatives were proposed as a photosensitizer for the photodeprotection of photosensitive groups in the light-directed in situ synthesis of biochip, which had overcome the conventional thinking that pyrene and derivatives could be only used as fluorescent labeling reagents, etc. This type of sensitizers not only can absorb certain wavelengths of ultraviolet light and transfer energy to the photosensitive groups, but also can be excited by some of the UV light to produce a similar wavelength fluorescence, which can provide a secondary exposure to the photosensitive groups, thus accelerating the photodeprotection rate.Appropriate solvents are also important factors in improving the photodeprotection efficiency. In this paper, on the base of the utilization of photosensitizers pyrene and its derivatives, the new method optimized the proportion of various solvents in the mixed photosensitive solution and improved the photodeprotection efficiency ultimately, which provides a new way of thinking for the photodeprotection of photosensitive groups under a low light intensity, and has broad prospects in the future.