4 research outputs found
Light Controllable Surface Coating for Effective Photothermal Killing of Bacteria
Although the electronic properties
of conducting films have been widely explored in optoelectronic fields,
the optical absorption abilities of surface-coated films for photothermal
conversion have been relatively less explored in the production of
antibacterial coatings. Here, we present catechol-conjugated poly(vinylpyrrolidone)
sulfobetaine (PVPS) and polyaniline (PANI) tightly linked by ionic
interaction (PVPS:PANI) as a novel photothermal antibacterial agent
for surface coating, which can absorb broadband near-infrared (NIR)
light. Taking advantage of the NIR light absorption, this coating
film can release eminent photothermal heat for the rapid killing of
surface bacteria. The NIR light triggers a sharp rise in photothermal
heat, providing the rapid and effective killing of 99.9% of the Gram-positive
and -negative bacteria tested within 3 min of NIR light exposure when
used at the concentration of 1 mg/mL. Although considerable progress
has been made in the design of antibacterial coatings, the user control
of NIR-irradiated rapid photothermal destruction of surface bacteria
holds increasing attention beyond the traditional boundaries of typical
antibacterial surfaces
Determination of Cancer Cell-Based pH-Sensitive Fluorescent Carbon Nanoparticles of Cross-Linked Polydopamine by Fluorescence Sensing of Alkaline Phosphatase Activity on Coated Surfaces and Aqueous Solution
The tumor-specific sensitive fluorescence
sensing of cellular alkaline
phosphatase (ALP) activity on the basis of host–guest specific
and pH sensitivity was conducted on coated surfaces and aqueous states.
Cross-linked fluorescent nanoparticles (C-FNP) consisting of β-cyclodextrin
(β-CD)/boronic acid (BA) and fluorescent hyaluronic acid [FNP(HA)]
were conjugated to fluorescent polydopamine [FNP(pDA)]. To determine
the quenching effect of this system, hydrolysis of 4-nitrophenyl phosphate
(NPP) to 4-nitrophenol (NP) was performed in the cavity of β-CD
in the presence of ALP activated photoinduced electron transfer (PET)
between NP and C-FNP. At an ALP level of 30–1000 U/L, NP caused
off-emission of C-FNP because of their specific host–guest
recognition. Fluorescence can be recovered under pH shock due to cleavage
of the diol bond between β-CD and BA, resulting in release of
NP from the fluorescent system. Sensitivity of the assays was assessed
by confocal imaging not only in aqueous states, but also for the first
time on coated surfaces in MDAMB-231 and MDCK cells. This novel system
demonstrated high sensitivity to ALP through generation of good electron
donor/acceptor pair during the PET process. Therefore, this fluorescence
sensor system can be used to enhance ALP monitoring and cancer diagnosis
on both coated surfaces and in aqueous states in clinical settings
Visible-Light-Driven Photocatalysts of Perfluorinated Silica-Based Fluorescent Carbon Dot/TiO<sub>2</sub> for Tunable Hydrophilic–Hydrophobic Surfaces
In this study, a new hydrophilic–hydrophobic
transition
surface was designed via visible-light-induced photocatalytic perfluorinated
silica-based fluorescent carbon nanoparticles (FNPs)/TiO<sub>2</sub>. Perfluorinated silica–polydopamine hybrid FNPs (<i>f</i>-FNPs) were easily fabricated by carbonization in an emulsion
system consisting of tetraethyl orthosilicate and dopamine, followed
by the deposition of TiO<sub>2</sub> on <i>f</i>-FNPs, which
demonstrated the reversal from hydrophobic to hydrophilic nature during
successful photocatalysis. The synergistic effect of silica–carbon
and the deposited TiO<sub>2</sub> NPs led to the decomposition of
methylene blue under UV and visible light irradiation, demonstrating
that FNPs/TiO<sub>2</sub> sustains photocatalytic activity. The profound
contact angle with the catalytic kinetics curve and precise morphology
and extension of cells detach antifouling exceptionally unrestricted
the synergistic effect of silica–carbon on TiO<sub>2</sub> NPs
on a coated paper substrate. Given the interest in the manipulation
of hydrophobicity and hydrophilicity, this study can serve as a guideline
for the fabrication of photocatalytic surfaces where water spreads
completely
Highly Efficient Visible Blue-Emitting Black Phosphorus Quantum Dot: Mussel-Inspired Surface Functionalization for Bioapplications
The preparation of
blue-emitting black phosphorus quantum dots
(BPQDs) is based on the liquid-phase exfoliation of bulk BP. We report
the synthesis of soluble BPQDs showing a strong visible blue-light
emission. Highly fluorescent (photoluminescence quantum yield of ≈5%
with the maximum emission (λ<sub>max</sub>) at ≈437 nm)
and dispersible BPQDs in various organic solvents are first prepared
by simple ultrasonication of BP crystals in chloroform in the ambient
atmosphere. Furthermore, simple mussel-inspired surface functionalization
of BPQDs with catechol-grafted poly(ethylene glycol) in basic buffer
afforded water-soluble blue-emitting BPQDs showing long-term fluorescence
stability, very low cytotoxicity, and excellent fluorescence live
cell imaging capability