The determination of indoor formaldehyde is of great importance to protect individuals against its well-known adverse impact on health. Here, we report on a design of a naked-eye readout self-powered electrochemical biosensor (SPEB) toward gaseous formaldehyde based on the efficient catalytic activity of the formaldehyde dehydrogenase/poly (methylene green)/buckypaper bioanode and the excellent electrochromic property of the Prussian blue (PB) cathode. The SPEB has a planar configuration and is covered with poly(vinyl alcohol) (PVA) as gel electrolyte to provide an inner lateral resistance large enough to enable the progressive discoloration of the patterned PB at cathode, which in turn, making the determination of gaseous formaldehyde feasible by measuring the distance consumed after 10-min exposure. The use of PVA gel electrolyte can also facilitate the observation of the color change due to its excellent transparency. The SPEB shows obvious responses to gaseous formaldehyde in a broad concentration range of 80 and 3000 ppb, covering the important permissible limits of indoor formaldehyde related to human health. The SPEB also exhibits satisfactory results in sensing gaseous formaldehyde released from the real plywood that is one of the dominating sources of the gaseous indoor formaldehyde. The results shown here demonstrate the good potential of the naked-eye readout SPEB as a fast, reliable, and portable tool for on-site determination of gaseous formaldehyde, with the appealing characteristics such as ease of operation, simplicity of configuration, and no requirement of external power sources.

室内甲醛的测定对于保护个人免受众所周知的对健康的不利影响非常重要。在此，我们基于甲醛脱氢酶/聚（亚甲基绿）/巴基纸生物阳极的高效催化活性和其优异的电致变色特性，报告了针对气态甲醛的肉眼读出自供电式电化学生物传感器（SPEB）的设计。普鲁士蓝（PB）阴极。SPEB具有平面结构，并覆盖有聚乙烯醇（PVA）作为凝胶电解质，可提供足够大的内部侧向电阻，以使图案化PB在阴极处逐渐变色，进而确定气态通过测量暴露10分钟后消耗的距离可以得出甲醛。由于PVA凝胶电解质具有出色的透明性，因此也可以促进颜色变化的观察。SPEB在80到3000 ppb的宽浓度范围内显示出对气态甲醛的明显响应，涵盖了与人体健康相关的室内甲醛的重要允许限值。SPEB在感测从真正的胶合板释放的气态甲醛方面也显示出令人满意的结果，后者是气态室内甲醛的主要来源之一。此处显示的结果证明了裸眼读数SPEB作为一种快速，可靠且便携式的现场气态甲醛测定工具具有良好的潜力，并且具有易于操作，配置简单且不需要的吸引人的特征。外部电源。