Bacillus anthracis is a fatal biological warfare agent, with a mortality rate of almost 100% when the bacteria are inhaled. Therefore, developing a biosensor for rapidly detecting B. anthracis spores in the ambient air is critical. Conventional techniques tend to be time-consuming, labor-intensive, and require highly trained personnel, thereby preventing rapid onsite detection. Moreover, low-cost, stable probes are required for continuous monitoring of multiple airborne targets. This study presents a paper-based electrochemical peptide sensor for rapid, label-free, sensitive, and economical quantification of liquid-borne and airborne Bacillus subtilis spores, widely used nonpathogenic B. anthracis simulant spores. These sensors were fabricated using wax printing on Whatman filter paper along with stencil-printed carbon paste electrodes and Ag/AgCl ink, as well as subsequent peptide (NHFLPKV) immobilization. These low-cost quickly fabricated sensors were characterized by differential pulse voltammetry and could detect spore concentrations as low as 6.9 × 10² colony-forming units (CFU) mL^-1 in 30 min with high specificity towards the spores and stability. Furthermore, spore concentrations were determined from air samples obtained using the BioSampler, which demonstrated that these measurements agreed with those using the plate-counting assay; therefore, the surface proteins of the spores were intact through sampling with the BioSampler. These paper-based peptide sensors can be used for onsite rapid and continuous airborne spore-monitoring systems.

炭疽芽孢杆菌是一种致命的生物战剂，吸入细菌后死亡率几乎为 100%。因此，开发一种用于快速检测环境空气中炭疽芽孢杆菌孢子的生物传感器至关重要。传统技术往往费时、费力，并且需要训练有素的人员，因此无法快速进行现场检测。此外，需要低成本、稳定的探头来连续监测多个空中目标。本研究提出了一种纸基电化学肽传感器，可快速、无标记、灵敏且经济地定量液体传播和空气传播的枯草芽孢杆菌孢子，广泛使用的非致病性炭疽芽孢杆菌模拟孢子。这些传感器是使用 Whatman 滤纸上的蜡印以及模板印刷的碳糊电极和 Ag/AgCl 墨水以及随后的肽 (NHFLPKV) 固定来制造的。这些低成本快速制造的传感器以差分脉冲伏安法为特征，可以检测低至 6.9 × 10 ²菌落形成单位 (CFU) mL ^{-1 的}孢子浓度在 30 分钟内对孢子具有高度的特异性和稳定性。此外，孢子浓度是从使用 BioSampler 获得的空气样本中确定的，这表明这些测量值与使用平板计数法的测量值一致；因此，通过 BioSampler 采样，孢子的表面蛋白是完整的。这些纸基肽传感器可用于现场快速和连续的空中孢子监测系统。