Optical Bionanosensors for Sepsis Diagnostics.

Sepsis is a global health challenge, characterized by a dysregulated immune response, leading to organ dysfunction and death. Despite advances in medical care, sepsis continues to claim a significant toll on human lives, with mortality rates from 10-25% for sepsis and 30-50% for septic shock, making it a leading cause of death worldwide. Current diagnostic methods rely on clinical signs, laboratory parameters, or microbial cultures and suffer from delays and inaccuracies.

Signal Amplification and Near-Infrared Translation of Enzymatic Reactions by Nanosensors.

Enzymatic reactions are used to detect analytes in a range of biochemical methods. To measure the presence of an analyte, the enzyme is conjugated to a recognition unit and converts a substrate into a (colored) product that is detectable by visible (VIS) light. Thus, the lowest enzymatic turnover that can be detected sets a limit on sensitivity.

Near-Infrared Fluorescent Biosensors Based on Covalent DNA Anchors.

Semiconducting single-walled carbon nanotubes (SWCNTs) are versatile near-infrared (NIR) fluorophores. They are noncovalently modified to create sensors that change their fluorescence when interacting with biomolecules. However, noncovalent chemistry has several limitations and prevents a consistent way to molecular recognition and reliable signal transduction.

High Sensitivity Near-Infrared Imaging of Fluorescent Nanosensors.

Biochemical processes are fast and occur on small-length scales, which makes them difficult to measure. Optical nanosensors based on single-wall carbon nanotubes (SWCNTs) are able to capture such dynamics. They fluoresce in the near-infrared (NIR, 850-1700 nm) tissue transparency window and the emission wavelength depends on their chirality.

Comparison of electrical and optical transduction modes of DNA-wrapped SWCNT nanosensors for the reversible detection of neurotransmitters.

In this study, we compare the electrical and optical signal transduction of nanoscale biosensors based on single-walled carbon nanotubes (SWCNTs). Solution processable single-stranded (ss) DNA-wrapped SWCNTs were used for the fabrication of the distinct sensors. For electrical measurements, SWCNTs were assembled from solution onto pre-patterned electrodes by electric-field-assisted assembly in field-effect transistor (FET) configuration.