We have developed highly modular amphiphilic polymer-dendron hybrids composed of hydrophobic dendrons and hydrophilic linear polymer (e.g. polyethylene glycol (PEG)) that can be synthesized with a high degree of structural precision for suspending SWCNTs in an aqueous solution. Utilizing the susceptibility of the dendritic block of these amphiphiles toward enzymatic degradation, we demonstrated the ability to apply them for monitoring enzymatic activity in real-time through changes in the SWCNT fluorescent signal.

Figure 1: Schematic highlighting the degradation of PEG-dendron hybrid suspended SWCNTs via enzyme activity, leading to modulation in the fluorescence of the SWNCTs.

Advantages over existing technologies:
Traditionally, enzymes’ activity is tracked using chemically interactive probes operating in the UV-visible region. However, there are clear advantages to developing spectroscopic probes designed for NIR operation, as biological components exhibit high transparency in this spectral region. The use of NIR fluorescent probes allows for background-free monitoring of enzymatic activity. SWCNTs, known for their fluorescence in the NIR region, present a compelling option for such probes, especially when evaluating enzymatic activity in complex biological fluids. We have strategically functionalized SWCNTs with linear-dendrons amphiphiles bearing a chemical bond susceptible to hydrolysis by a specific enzyme. This enables real-time enzyme activity monitoring in the NIR region.

Future Applications:
The technologies described above rely on fundamental principles of SWCNT functionalization using selected molecules. This modular platform of configurable functional composite nanomaterials offers the opportunity to tailor it for numerous applications when detecting enzymatic activity or the presence of specific proteins are required, through the transient modulation of the fluorescence emission in the NIR. This versatility stems from the ability to rationally design the surface coatings of SWCNTs by tailoring the dendron block to the target enzyme (or protein).

Intellectual Property
US patent pending

Reference:
Wulf, V.; Slor, G.; Rathee, P.; Amir, R. J.; Bisker, G., Dendron–Polymer Hybrids as Tailorable Responsive Coronae of Single-Walled Carbon Nanotubes. ACS Nano 2021, 15 (12), 20539-20549. DOI 10.1021/acsnano.1c09125.