用于果蔬表面有机磷农残原位快速检测的纸基电化学传感体系的构建和检测机理研究

The existing rapid detection technologies of pesticide residues can not realize in-situ quantitative detection to meet the actual detection needs and ensure food safety practically. Electrochemical biosensor for pesticide residues is rapid and sensitive, with the potential for achieving in-situ detection. From the perspectives of electrode structure and detection technology, this project plans to innovatively replace traditional base substrate of electrode carrier with paper materials which were widely used in the field of detection recently years and prepare electrode template with a specific shape through paper-based microfluidic technology, to introduce enzymes used for pesticide residues detection based on the existing researches of conductive ink and develop out electrode inks and enzyme ink which can maintain enzyme activity well, have high conductivity, strong surface adhesion ability through the nanomaterials preparation and modification technology, produced paper-based detecting electrode by coating the resultant inks on paper-based template, to improve detection signal of paper-based sensor via utilizing the new electrochemical detection technology that is local redox cycling-based electrochemical detection, so as to achieve the in-situ rapid detection of organophosphorus pesticide residues on fruits and vegetables surface. A low-cost, operable, sensitive and rapid detection system for in-situ pesticide residues detection could be established through the systematic studies on the construction and detection mechanisms of the paper-based electrochemical biosensing system, providing new research ideas and basics for the development on rapid detection of pesticide residues which is applicable to "real-time" testing requirements of agricultural products in China.

现有的农残快速检测技术无法实现原位定量检测，不能满足实际检测需要、切实保障食品安全。农残电化学生物传感器快速灵敏，具有实现原位检测的潜能。本项目拟从传感器的电极结构和检测技术角度出发，创新性地用近年来在检测领域应用广泛的纸材料代替传统基底电极载体，利用纸基微流控技术制备出具有特定形状的电极模版；在现有导电墨水的研究基础上引入农残检测用酶，通过纳米材料制备与修饰技术研发出能够保持酶活性、具有高电导率和强表面粘附力的酶墨水和电极墨水，涂覆于纸基模版制备纸基检测电极；结合新型的基于局部氧化还原的循环电化学检测技术提高纸基传感器的检测信号；从而实现果蔬表面有机磷农残的原位快速检测。通过系统研究纸基农残电化学生物传感体系的构建和检测机理建立一种低成本、可操作性强、灵敏快速的原位农残快速检测系统，为研发适用于我国农产品“现场即时”检测需求的农残快速检测技术提供新的研究思路和研究基础。

现有的农残快速检测技术不能满足实际检测需要、切实保障食品安全。农残电化学生物传感器快速灵敏，具有实现原位检测的潜能。本项目创新性地利用近年来在检测领域应用广泛的纸材料代替传统基底电极载体，将纸基微流控技术中的蜡染法和丝网印刷法有机结合制备出整合了三电极体系的电极模版；在现有导电墨水的研究基础上从提高生物相容性的角度出发，选用具有很高生物相容性的聚乙二醇作为酶墨水的粘合剂，添加具有高度生物相容性的壳聚糖既能增加酶墨水的粘附力也有助于延长酶墨水的保存时间，选用胶体石墨粉作为导电材料来提高酶墨水的导电性，选用木糖醇作为酶墨水中酶的生物相容性稳定剂，制备出具有良好生物相容性和导电性的基质墨水，利用银纳米颗粒偶联修饰乙酰胆碱酯酶，均匀分散于墨水基质中实现农残检测用酶的固定化，通过纳米材料制备与修饰技术研发出能够保持酶活性、具有高电导率和强表面粘附力的酶墨水和电极墨水，涂覆于纸基模版制备出了纸基检测电极；结合灵敏的电化学检测技术实现了果蔬表面有机磷农残的原位快速检测。通过系统研究纸基农残电化学生物传感体系的构建和检测机理建立一种低成本、可操作性强、灵敏快速的原位农残快速检测系统，为研发适用于我国农产品“现场即时”检测需求的农残快速检测技术提供新的研究思路和研究基础。