基于Exo III信号放大的荧光适配体传感器检测Kunitz型大豆胰蛋白酶抑制因子

Kunitz型大豆胰蛋白酶抑制因子（Kunitz Soybean Trypsin Inhibitor，KTI）是一种很关键的抗营养因子，不仅对动物消化系统和生长发育有不良影响，还制约各个行业对大豆的利用率，因此快速有效的检测方法是非常必要的。该研究建立一种基于核酸外切酶III（Exonuclease III，Exo III）和碳纳米颗粒（Carbon Nanoparticles，CNPs）的信号辅助放大荧光传感体系用于KTI的检测。具体体系包括KTI适配体（Aptamer，APT）、互补链（Complementary DNA，cDNA）、信号探针（Signal Probe，SP）、Exo III和CNPs共5个部分。通过可行性分析和CNPs浓度优化试验，测得KTI在100~600 ng/mL范围内呈线性相关，检测限为12.59 ng/mL。以豆浆作为样品，采用加标回收测得回收率为97.42%~102.85%，RSD在0.61%~2.36%之间，该方法可对实际样品中的KTI进行测定。

Detection of the Kunitz Soybean Trypsin Inhibitor Using a Fluorescence Aptamer Biosensor Based on Exo III Signal Amplification

The Kunitz soybean trypsin inhibitor (KTI) is a key antinutritional factor, which not only has adverse effects on the digestive system and growth of animals, but also restricts the utilization of soybean in various industries. Therefore, a rapid and effective detection method is imperative. In this study, a signal-assisted amplification fluorescence sensing system based on exonuclease III (Exo III) and carbon nanoparticles (CNPs) was established for the detection of KTI. The specific system consisted of the KTI aptamer (APT), complementary DNA (cDNA), signal probe (SP), Exo III, and CNPs. Through feasibility analysis and a CNP concentration optimization test, KTI was linearly correlated in the range of 100~600 ng/mL, and the detection limit was 12.59 ng/mL. The recovery rates of soybean milk were 97.42%~102.85% and the residual standard deviations were 0.61%~2.36%. This method can be used to determine KTI in actual samples.