Thesis (M.Sc.)--Chulalongkorn University, 2011

This research aims to design and synthesize the molecular sensors for nucleotides sensing. In the case of the energy transfer, gold nanoparticles were used to study on the complexation related two processes including i) the complexation of nucleotides with the modified gold nanoparticles and fluorophore and ii) the fluorophore replacement on the gold nanoparticles by nucleotides. Unfortunately, the detection of nucleotides using the concepts of the fluorescence quenching by gold nanoparticles under both processes has not been achieved. For nucleotides discrimination using Principal Component Analysis (PCA), the molecular sensors containing pyrene and coumarin derivatives (Pydpa and Es) were used for discrimination of various nucleotides in aqueous solution. Initially, the complexation of Pydpa-Zn, Pydpa-Cu, Es-Zn, and Es-Cu were prepared as the sensory molecules to recognize the phosphate anion based nucleotides undergone the electrostatic interaction. The complexation studies of these sensors were carried out by fluorescence spectrophotometry. It was found that Pydpa-Zn, Es-Zn, and Es-Cu showed a high selectivity to PPi with the log K values of 8.83, 5.23 and 4.64, respectively. In addition, the PCA method was applied to classify the types of nucleotides by creation of the sensor arrays (the combinatorial data) and the mixed sensors (the combinatorial sensors). Interestingly, the combinatorial sensors of Pydpa-Zn+Es-Cu showed a highly potential discrimination of PPi, ATP, UTP, ADP, UDP and GDP with 92% classification accuracy.