Design Of Data Acquisition System For Nanopore Single-molecule Detection

The nanopore single-molecule detection, as an efficient and rapid detection method, has drawn scientists’attention in recent years. Nanopore single-molecule detection technique is dedicated to studying the molecule’s structure and the weak interaction between molecules. Driven by the electric field, the single molecule passes through the nanopore and generates irons (pA), which is related to the molecule individual detail information. In order to analyze the irons, large amounts of data need to be acquired, stored, and analyzed. That requires high performance data acquisition system. This paper presents the architecture of the data acquisition system which is based on FPGA and USB2.0techniqueAccording to the requirement of the nanopore single-molecule detection system and feature of the signal, using the AD5547chip which can output wide range of different polarity voltage and designing the pre-processing circuit to handle the pre-amplifier’s output to meet the input requirements of ADC Chip (AD7685). Digital isolators, reasonable power supply and layout are used to reduce noise. Logical control is realized by using FPGA technique, achieving synchronizing output with input. And it’s convenient to communicate with PC by adopting USB technique. According to the system function, the FPGA logic is divided into multiple modules.At the end of this paper, tests show that the system is able to acquire data stably and meet the design goals, the noise from this system is under1mV(corresponding to1pA). At the same time, due to the noise influence the data seriously, this paper adopts the wavelet denoising to acquire the key value, and get the expected effect finally.