Options
2024
Journal Article
Title
Signal Amplification and NearāInfrared Translation of Enzymatic Reactions by Nanosensors
Abstract
Enzymatic reactions are used to detect analytes in a range of biochemical methods. To measure the presence of an analyte, they are conjugated to a recognition unit and convert 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. Here, we report that substrates and products of horseradish peroxidase (HRP) and Ī²āgalactosidase change the nearāinfrared (NIR) fluorescence of (bio)polymer modified singleāwalled carbon nanotubes (SWCNTs). They translate a VIS signal into a beneficial NIR signal. Moreover, the affinity of the nanosensors leads to a higher effective local concentration of the reactants. This causes a nonālinear sensorābased signal amplification and translation (SENSAT). We find signal enhancement up to ā 120x for the HRP substrate pāphenylenediamine (PPD), which means that reactions below the limit of detection in the VIS can be followed in the NIR (ā 1000 nm). The approach is also applicable to other substrates such as 3,3āā5,5āātetramethylbenzidine (TMB). An adsorptionābased theoretical model fits the observed signals and corroborates the sensorābased enhancement mechanism. This approach can be used to amplify signals, translate them into the NIR and increase sensitivity of biochemical assays.
Author(s)
Project(s)
Biohybride, hochsensitive Nanosensoren fĆ¼r die In-situ-Diagnostik in der Biomedizin und -Umweltanalyse