超灵敏检测中信号扰动分析及应用

Analysis and Application of Signal Fluctuation in Ultra-Sensitive Detection

摘要: 随着相关技术的发展，分析检测方法正在逐步向亚皮摩尔的检测限逼近的同时也面临一系列挑战。其中最大的挑战是目标分子或离子检测浓度的降低使相应的检测信号也降低，甚至有可能低于环境的背景噪音，以致于实际的检测信号被掩盖。为解决这一问题，关键在于提高检测技术的信噪比。因此，这篇综述主要探讨了超灵敏检测的进展和面临的挑战以及如何提高信噪比的方法。其中包括利用纳米孔和纳米通道的限域效应来放大目标检测物的信号的方法，但是仍然存在如何降低背景噪音的问题，因为限域的空间对信号放大是没有选择性的。另一种思路是利用噪音扰动分析，对检测信号进行时域或频域的相关处理，将其从背景噪音中分离，从而获得检测物的具体信息。最后，本综述结合这两个方面解决思路对超灵敏检测的未来发展作出了展望。

Abstract: The ultra-sensitive determination methods have been approaching to Sub-Picomolar detection limit as well as confronting a series of challenges, where the greatest challenge we have to overcome is that lower level of detected signal resulting from lower concentration of target molecules is normally masked by background noise. Improving signal to noise ratio (S/N ratio) of detection method is a critical solution to address this concern. Therefore, in this review, we summarized the recent advances and challenges in ultra-sensitive detection and discussed methods to improve S/N ratio. Applying nano-confined effect of nanopore and nanochannel to amplify detected signal of target molecules is an efficient strategy. Meanwhile, since background noise is also magnified, reducing background noise is still a limiting factor in developing ultra-sensitive detection. Another strategy is to separate detected signals that are masked by background signal by applying noise analysis with the help of numerical method. Finally, we provide a brief discussion about future trend in developing ultra-sensitive detection.