It is important to detect reactive oxygen species (ROS) in situ for investigation of various critical biological processes, and this is however very challenging because of the limited sensitivity or/and selectivity of existing methods that are mainly based on sensing ROS released by cells with short lifetimes and low concentrations in a culture medium. Here, a new approach is reported to directly grow living cells on DNA/Mn3(PO4)2‐immobilized and vertically aligned carbon nanotube (VACNT) array nanostructure as a smart free‐standing hybrid film, of which the DNA/Mn3(PO4)2 and VACNT provide high electroactivity and excellent electron transport, respectively, while the directly grown cell on the nanostructure offers short diffusion distance to reaction sites, thus constructing a highly sensitive in situ method for detection of cancer‐cell‐released ROS under drug stimulations. Compared to the measured ROS released by cells in a culture medium, the detection sensitivity with this constructed hybrid film increases by more than six times, which implies that ROS molecules (superoxide anions) secreted from living cells are immediately captured by this smart structure without diffusion process or with extremely short diffusion distance. This design considerably reduces the time from release to detection of the target molecules, minimizing the potential molecular decay due to the short lifetime or high reactivity.
To
enlarge the surface-enhanced Raman scattering (SERS) enhancement
of Ag nanopillar arrays, a well-controlled armrest Ag NRs@Al2O3 structure was designed, aiming at triggering efficient
resonance between the nanopillar and the Ag NRs. A series of armrest
Ag NRs@Al2O3 with well-designed morphology as
well as enhanced “hot spots” quantity by taking advantage
of AAO template and oblique angle deposition were successfully fabricated.
Both experimental results and numerical simulations revealed localized
surface plasmon resonance (LSPR) tunability by simply optimizing the
arm length. An optimal substrate with outstanding SERS performance
for dyes and biomolecular was realized by enhancing the hot spots
area while tuning the resonance peak close to the 785 nm excitation.
The as-fabricated 14-Ag NRs@Al2O3 without any
surface modification presented a glucose detection limit of 1 ×
10–4 mM, endowing our SERS platform for sensitive
label-free biodetection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.