Surface plasmon-enhanced fluorescence and surface-enhanced Raman scattering dual-readout chip constructed with silver nanowires: Label-free clinical detection of direct-bilirubin

It has been found that the direct/total bilirubin ratio (D/T-BIL) is related to the survival rate of COVID-19 pneumonia. The presence of an excessive amount of bilirubin in human blood also causes liver and neurological damage, leading to death. Therefore, upon considering the adverse impact of the presence of excessive bilirubin in human blood, it has become highly imperative to detect bilirubin in a fast and label-free manner. Herein, we designed and constructed a random-crossed-woodpile nanostructure from silver nanowires to form a 3-dimensional plasmonic hotspot-rich (3D-PHS) nanostructure and successfully used it to detect direct bilirubin (D-BIL) in human blood in a label-free manner. The 3D-PHS nanochip provides rich spatial hot spots that are simultaneously responsive to SERS and SPEF effects and consequently, successfully used to measure and characterize D-BIL with a detection limit of similar to 10 nM, requiring only 10 mu L of human serum for rapid screening, which is the first time D-BIL has been detected in a clinically relevant range. This demonstrates a simple, label-free, pre-treatment-free potential biosensing technology that can be used in health care units, and further, in the efficient detection of point-of-care testing with a portable spectrometer.

Automated summary

The D/T-BIL ratio is related to the survival rate of COVID-19 pneumonia, as excessive bilirubin in human blood can cause liver and neurological damage. Therefore, it is imperative to detect bilirubin in a fast and label-free manner. A 3D-PHS nanochip was designed and successfully used to detect D-BIL in human blood without labels, showcasing a potential biosensing technology for health care units and point-of-care testing.