“…Over the past few years, several studies based on the metal nanoparticle aggregation method has been demonstrated as colorimetric assays for detection of various analytes such as Vc, alkaline phosphatase, etc. [52][53][54] Combining the redoxresponsive properties of the PFS polymer and the interparticle distance dependent SPR properties of AuNPs, we propose the application of PFS − @AuNPs for the detection of reversible redox reactions with a colour change as a readout signal to indicate the concentration of the analyte. To this end, we investigated the suitability of well-dispersed PFS − @AuNPs as a colorimetric probe for the detection of the oxidizing agent (FeCl 3 ) and the reducing agent, ascorbic acid, (Vit C) in homogeneous solutions.…”
Gold nanoparticles (AuNPs) coated with responsive polymers gained considerable interest due to their controllable size, good stability, and fast environmental response suitable for biological applications and sensing. Here we report on a simple and efficient method for the synthesis of stable and redox responsive AuNPs using organometallic polyelectrolytes in aqueous solutions of HAuCl. In the redox reaction, positively or negatively charged poly(ferrocenylsilanes) (PFS/PFS) served as reducing agents, and also as stabilizing polymers. Due to their unique tunable electrostatic and electrosteric protection, AuNPs coated with PFS, (PFS)@AuNPs, possess high redox sensitivity, with reversible, repetitive, sustainable color switching between the assembled (purple color) and disassembled (red color) states as evidenced by UV-Vis absorption and TEM measurements. Feasibility studies reported here indicate that the particles described can be applied as a colorimetric probe for the detection of redox molecules, e.g. vitamin C, in a controlled and facile manner.
“…Over the past few years, several studies based on the metal nanoparticle aggregation method has been demonstrated as colorimetric assays for detection of various analytes such as Vc, alkaline phosphatase, etc. [52][53][54] Combining the redoxresponsive properties of the PFS polymer and the interparticle distance dependent SPR properties of AuNPs, we propose the application of PFS − @AuNPs for the detection of reversible redox reactions with a colour change as a readout signal to indicate the concentration of the analyte. To this end, we investigated the suitability of well-dispersed PFS − @AuNPs as a colorimetric probe for the detection of the oxidizing agent (FeCl 3 ) and the reducing agent, ascorbic acid, (Vit C) in homogeneous solutions.…”
Gold nanoparticles (AuNPs) coated with responsive polymers gained considerable interest due to their controllable size, good stability, and fast environmental response suitable for biological applications and sensing. Here we report on a simple and efficient method for the synthesis of stable and redox responsive AuNPs using organometallic polyelectrolytes in aqueous solutions of HAuCl. In the redox reaction, positively or negatively charged poly(ferrocenylsilanes) (PFS/PFS) served as reducing agents, and also as stabilizing polymers. Due to their unique tunable electrostatic and electrosteric protection, AuNPs coated with PFS, (PFS)@AuNPs, possess high redox sensitivity, with reversible, repetitive, sustainable color switching between the assembled (purple color) and disassembled (red color) states as evidenced by UV-Vis absorption and TEM measurements. Feasibility studies reported here indicate that the particles described can be applied as a colorimetric probe for the detection of redox molecules, e.g. vitamin C, in a controlled and facile manner.
“…Compared to other sensors reported for AA detection (Table I), ATP-Ce-Tris fluorescence probe displays the better sensitivity. 2,39 Figure 5.(a) Fluorescence responses of ATP-Ce-Tris (0.025 μM) upon addition of various concentrations of AA (bottom to top, 0, 0.05, 0.1, 0.5, 1, 5, 10, 50, 100, 200, and 500 μM) in Tris-HCl buffer (50 mM, pH 7.4), λ ex = 270 nm. Insert picture shows the Logarithmic value of fluorescence intensities of ATP-Ce-Tris as a function of the concentration of AA (b).…”
Section: Resultsmentioning
confidence: 99%
“…Compared to other sensors reported for AA detection (Table I), ATP-Ce-Tris fluorescence probe displays the better sensitivity. 2,39 In view of that the matrix effect in practical systems may also quench the fluorescence as Fe 3þ ions, we examined the fluorescence intensity of ATP-Ce-Tris samples before and after added the human serum (Fig. S7, Supplemental Material).…”
Section: Sensing System For Ascorbic Acidmentioning
Ascorbic acid (AA), or vitamin C, is an important reactive biological molecule in vivo, and an abnormal level of AA is associated with many diseases. Therefore, the rapid, sensitive, and selective detection of AA levels is of significance in cases of medical assay and diagnosis. Compared with other nanoparticles, lanthanide coordination polymer nanoparticles (Ln-CPs) have been demonstrated as the excellent biomolecule sensing platforms due to their unique optical properties and intrinsic porosities. In this work, the cerium coordination polymer nanoparticles ATP-Ce-Tris were synthesized in a simple and quick way. The synthesized ATP-Ce-Tris nanoparticle shows the characteristic peak of Ce3+ located at 365 nm, which is corresponding to the 4f→5d transition of Ce3+. In the presence of Fe3+, the fluorescence of ATP-Ce-Tris quenched, and the following added ascorbic acid (AA) makes it restoring effectively. Based on this, we constructed a fluorescence probe with excellent sensitivity for AA sensing in a wide linear relationship from 0.05 to 500 μM. The detection limit was as low as 18 nM (signal-to-noise ratio of three), which is one or two orders of magnitude lower than those of reported sensors. The proposed sensing systems also exhibits excellent sensitivity for AA detection in human serum sample, exploiting a valuable platform for AA analysis in clinic diagnostic and drug screening.
Metal‐based nanoentities, apart from being indispensable research tools, have found extensive use in the industrial and biomedical arena. Because their biological impacts are governed by factors such as size, shape, and composition, such issues must be taken into account when these materials are incorporated into multi‐component ensembles for clinical applications. The size and shape (rods, wires, sheets, tubes, and cages) of metallic nanostructures influence cell viability by virtue of their varied geometry and physicochemical interactions with mammalian cell membranes. The anisotropic properties of nonspherical metal‐based nanoarchitectures render them exciting candidates for biomedical applications. Here, the size‐, shape‐, and composition‐dependent properties of nonspherical metal‐based nanoarchitectures are reviewed in the context of their potential applications in cancer diagnostics and therapeutics, as well as, in regenerative medicine. Strategies for the synthesis of nonspherical metal‐based nanoarchitectures and their cytotoxicity and immunological profiles are also comprehensively appraised.
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