The emergence of the coronavirus disease 2019 (COVID-19)
pandemic
prompted researchers to develop portable biosensing platforms, anticipating
to detect the analyte in a label-free, direct, and simple manner,
for deploying on site to prevent the spread of the infectious disease.
Herein, we developed a facile wavelength-based SPR sensor built with
the aid of a 3D printing technology and synthesized air-stable NIR-emitting
perovskite nanocomposites as the light source. The simple synthesis
processes for the perovskite quantum dots enabled low-cost and large-area
production and good emission stability. The integration of the two
technologies enabled the proposed SPR sensor to exhibit the characteristics
of lightweight, compactness, and being without a plug, just fitting
the requirements of on-site detection. Experimentally, the detection
limit of the proposed NIR SPR biosensor for refractive index change
reached the 10–6 RIU level, comparable with that
of state-of-the-art portable SPR sensors. In addition, the bio-applicability
of the platform was validated by incorporating a homemade high-affinity
polyclonal antibody toward the SARS-CoV-2 spike protein. The results
demonstrated that the proposed system was capable of discriminating
between clinical swab samples collected from COVID-19 patients and
healthy subjects because the used polyclonal antibody exhibited high
specificity against SARS-CoV-2. Most importantly, the whole measurement
process not only took less than 15 min but also needed no complex
procedures or multiple reagents. We believe that the findings disclosed
in this work can open an avenue in the field of on-site detection
for highly pathogenic viruses.