提高芯片毛细管电泳系统检测信噪比的哈达玛变换法

Enhancement of Signal-to-Noise Ratio in Chip-based Capillary Electrophoresis Systems by a Hadamard Transform Approach

采用门控进样 ,在简单的十字通道微流控玻璃芯片上实现了假随机多次进样 ,研究了利用哈达玛变换提高微流控毛细管电泳分析系统信噪比的方法 .在实验中 ,以 7阶 1 2 7步假随机二进制序列作为进样模板 ,将缓冲液和 Cy5衍生后的氨基酸试样交替注入到分离通道中 ,检测到的电泳信号经过哈达玛反变换还原使信噪比提高 5倍 (理论上 5 .6倍 )的电泳谱 ,各组分的出峰时间、峰高和峰形均完全还原 ,毛细管电泳分离的采样频率不受影响 .

The first demonstration of Hadamard transform capillary electrophoresis(CE) is reported for enhancing the signal-to-noise ratios(S/N) on a microfluidic chip using a simple electrokinetically gated injection approach in this paper. Sample or running buffer was alternatively injected into the separation channel according to a 7-bit, 127-step pseudorandom binary sequence(PRBS). The electrophoregram rebuilt from detector signal with inverse Hadamard transform improved the S/N ratio by a factor of 5(5.6 in theory), compared to conventional single injection electrophoregram, almost without affecting the sample throughput.