1.
Rectangular coordination polymer nanoplates: large-scale, rapid synthesis and their application as a fluorescent sensing platform for DNA detection.
Zhang, Y, Luo, Y, Tian, J, Asiri, AM, Al-Youbi, AO, Sun, X
PloS one. 2012;(1):e30426
Abstract
In this paper, we report on the large-scale, rapid synthesis of uniform rectangular coordination polymer nanoplates (RCPNs) assembled from Cu(II) and 4,4'-bipyridine for the first time. We further demonstrate that such RCPNs can be used as a very effective fluorescent sensing platform for multiple DNA detection with a detection limit as low as 30 pM and a high selectivity down to single-base mismatch. The DNA detection is accomplished by the following two steps: (1) RCPN binds dye-labeled single-stranded DNA (ssDNA) probe, which brings dye and RCPN into close proximity, leading to fluorescence quenching; (2) Specific hybridization of the probe with its target generates a double-stranded DNA (dsDNA) which detaches from RCPN, leading to fluorescence recovery. It suggests that this sensing system can well discriminate complementary and mismatched DNA sequences. The exact mechanism of fluorescence quenching involved is elucidated experimentally and its use in a human blood serum system is also demonstrated successfully.
2.
Artificial neural network-genetic algorithm based optimization for the immobilization of cellulase on the smart polymer Eudragit L-100.
Zhang, Y, Xu, J, Yuan, Z, Xu, H, Yu, Q
Bioresource technology. 2010;(9):3153-8
Abstract
Cellulase was covalently immobilized on a smart polymer, Eudragit L-100 by carbodiimide coupling. Using data of central composite design, response surface methodology (RSM) and artificial neural network (ANN) were developed to investigate the effect of pH, carbodiimide concentration, and coupling time on the activity yield of immobilized cellulase. Results showed simulation and prediction accuracy of ANN was apparently higher compared to RSM. The maximum activity yield obtained from RSM was 57.56% at pH 5.54, carbodiimide concentration 0.32%, and coupling time 3.03 h, where the experimental value was 60.87 + or - 4.79%. Using ANN as fitness function, a maximum activity yield of 69.83% was searched by genetic algorithm at pH 5.07, carbodiimide concentration 0.36%, and coupling time 4.10 h, where the experimental value was 66.75 + or - 5.21%. ANN gave a 9.7% increase of activity yield over RSM. After reusing immobilized cellulase for 5 cycles, the remaining productivity was over 50%.