Plasmonic nanocrystals on polycarbonate substrates for direct and label-free biodetection of Interleukin-6 in bioengineered 3D skeletal muscles

Abstract The development of nanostructured plasmonic biosensors has been widely widespread in the last years, motivated by potential benefits they can offer integration, miniaturization, multiplexing opportunities, and enhanced performance label-free biodetection a wide field applications. Between them, engineering tissues represent novel, challenging, prolific application for considering previously described low levels secreted biomarkers (≈pM–nM) to detect. Here, we present an integrated nanocrystals-based biosensor using high throughput polycarbonate substrates. Metallic film thickness incident angle light reflectance measurements were optimized enhance detection antibody–antigen biorecognition events numerical simulations. We achieved enhancement up 3× as decreases, which be related shorter evanescent decay lengths. reproducibility between channels with coefficient variation below 2% bulk refractive index measurements, demonstrating multiplexed sensing. Finally, biosensing was demonstrated direct interleukin-6 biomarker undiluted cell culture media supernatants from bioengineered 3D skeletal muscle stimulated different concentrations endotoxins achieving limit (LOD) ≈ 0.03 ng/mL (1.4 pM).