Carbon nanotube–interfaced lab-on-a-chip sensor coupled with a quantum dot sandwich assay for rapid and selective detection of airborne Aspergillus fumigatus spores

Official URL: https://dx.doi.org/10.1016/j.cej.2026.180185

Airborne fungal pathogens, specifically Aspergillus fumigatus represent a critical threat to public health, particularly for immunocompromised individuals indoor and hospital environments. Conventional detection methods are often labor-intensive, time-consuming and unsuitable for real-time monitoring. Herein, we report a rapid and selective detection platform utilizing carbon nanotube (CNT)–interfaced lab-on-a-chip (LoC) electrochemical biosensor coupled with a quantum dot (QD)–assisted dual-recognition sandwich assay. This sensor features gold interdigitated microelectrode arrays functionalized with anti-Asp f antibodies for selective spore capture. To enhance the signal generation, the system employs a hierarchical sensing interface (Au–CNT–Ab₁⟨Spore⟩Ab₂/QD–Fibrinogen) that mimics host-pathogen recognition by using QDs conjugated with both anti-Asp f antibodies and fibrinogen protein. This dual-recognition mechanism transforms the sensing process from steric current blocking to electrochemical signal amplification, resulting a linear amperometric response across a concentration range of 102–106 spores/mL. The platform achieved a detection limit of ∼109 spores/mL and demonstrated high specificity, showing negligible response to non-target fungal strains. Further, a customized aerosol collection unit allows for controlled aerosolization, condensation and dispensing for direct electrochemical detection of airborne spores on the sensor surface. This work establishes a synergistically integrated nano-bioelectronic platform that combines CNT-enhanced conductivity, QD-mediated amplification, and selective biological recognition for the real-time surveillance of airborne fungal pathogens.