ON-SITE AIRBORNE PATHOGEN MONITORING AND PROFILING USING PAPER-BASED ELECTROCHEMICAL BIOSENSORS

Abstract

Infectious respiratory diseases transmitted by bioaerosols impose substantial public-health and economic burdens. Yet airborne pathogens are typically dilute and susceptible to sampling induced damage, hindering rapid and reliable quantification. Here, we present an integrated framework that couples paper-based electrochemical biosensors with purpose-built aerosol concentrators to enable low-cost, on-site monitoring and mechanistic profiling of airborne pathogens. First, we engineered a peptide-functionalized paper-based sensor for Bacillus spores that delivers 30-min, label-free quantification across 6.9 × 10^2–10^6 CFU/mL (LOD = 6.9 × 10^2 CFU/mL), exhibits species selectivity and four-week stability, and agrees with culture-based for impinger-collected air samples. Second, we developed a growth-based virus aerosol concentrator (GVC; 6 L/min) that condenses water onto submicron virus particles, enlarging them to 1.5 μm to achieve over 90% physical capture while mitigating impact stress. Combined with paper-based electrochemical immunosensors targeting influenza A hemagglutinin (HA) and nucleoprotein (NP), this platform attained enrichment ratios over 10^5 and sensor LODs of 8.6 and 4.1 PFU/mL (HA and NP, respectively), enabling classroom measurements spanning 10–10^6 copies/m^3. Simultaneous HA/NP readouts yielded a quantitative integrity metric-loss of HA antigenicity (LHA)-ranging from 48–75%, linking environmental sampling conditions to infectivity. Finally, to extend coverage to larger volumes and multiple viruses, we built an electrostatic viral aerosol concentrator (EVAC; 40 L/min) and paired it with paper-based electrochemical immunosensors and RT-PCR for human adenovirus type 3, respiratory syncytial virus A, and influenza A virus H1N1. The system achieved RT-PCR-comparable detection limits while revealing viral species-dependent differences in intrinsic collection efficiency and susceptibility to electrostatic stress, which explain divergences between protein- and genome-based quantification. Collectively, these studies delineate a rigorously validated sampler-sensor architecture for monitoring and profiling airborne pathogens. Paper-based electrochemical biosensors deliver rapid and reliable quantitative readouts and demonstrate robust performance under field conditions. By intercomparing samplers with distinct collection mechanisms across pathogen types, we define pathogen-aware analytical pathways and operational regimes.