Department of Pharmacy, University of Naples Federico II, Naples, Italy.
Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome, Italy.
Nat Protoc. 2019 Aug;14(8):2437-2451. doi: 10.1038/s41596-019-0186-y. Epub 2019 Jul 3.
Despite substantial advances in sensing technologies, the development, preparation, and use of self-testing devices is still confined to specialist laboratories and users. Decentralized analytical devices will enormously impact daily lives, enabling people to analyze diverse clinical, environmental, and food samples, evaluate them and make predictions to improve quality of life, particularly in remote, resource-scarce areas. In recent years, paper-based analytical tools have attracted a great deal of attention; the well-known properties of paper, such as abundance, affordability, lightness, and biodegradability, combined with features of printed electrochemical sensors, have enabled the development of sustainable devices that drive (bio)sensors beyond the state of the art. Their blindness toward colored/turbid matrices (i.e., blood, soil), their portability, and the capacity of paper to autonomously filter/purge/react with target species make such devices powerful in establishing point-of-need tools for use by non-specialists. This protocol describes the preparation of a voltammetric phosphate sensor and an amperometric nerve agent biosensor; both platforms produce quantitative measurements with currents in the range of microamperes. These printed strips comprise three electrodes (graphite for working and counter electrodes and silver/silver chloride (Ag/AgCl) for the reference electrode) and nanomodifiers (carbon black and Prussian blue) to improve their performance and specificity. Depending on analytical need, different types of paper (filter, office) and configurations (1D, 2D, 3D) can be adopted. The protocol, based on the use of cost-effective manufacturing techniques such as drop casting (to chemically modify the substrate surface) and wax/screen printing (for creating the channels and electrodes), can be completed in <1 h.
尽管传感技术取得了重大进展，但自我检测设备的开发、准备和使用仍然局限于专业实验室和用户。分散式分析设备将极大地影响人们的日常生活，使人们能够分析各种临床、环境和食品样本，对其进行评估并做出预测，从而提高生活质量，特别是在偏远、资源匮乏的地区。近年来，基于纸张的分析工具引起了广泛关注；纸张的众所周知的特性，如丰富、经济实惠、轻便和可生物降解性，结合印刷电化学传感器的特点，使得可持续发展的设备得以开发，从而推动（生物）传感器超越现有技术水平。它们对有色/混浊基质（即血液、土壤）的盲目性、便携性以及纸张自主过滤/清除/与目标物种反应的能力，使得这些设备非常适合用于非专业人员的即时检测工具。本方案描述了伏安法磷酸盐传感器和安培法神经毒剂生物传感器的制备；这两种平台都能产生微安级电流范围内的定量测量。这些印刷条带包括三个电极（用于工作和对电极的石墨以及用于参比电极的银/氯化银（Ag/AgCl））和纳米修饰剂（炭黑和普鲁士蓝），以提高其性能和特异性。根据分析需求，可以采用不同类型的纸张（过滤纸、办公纸）和不同的结构（1D、2D、3D）。该方案基于使用经济实惠的制造技术，如滴铸（用于化学修饰基底表面）和蜡/丝网印刷（用于创建通道和电极），可在<1 小时内完成。
