3 research outputs found
Novel Magnetic Microprobe with Benzoboroxole-Modified Flexible Multisite Arm for High-Efficiency <i>cis</i>-Diol Biomolecule Detection
With
regard to regulating a variety of biological events, including
molecular recognition, signal transduction, cell adhesion, and immune
response, <i>cis</i>-diol biomolecules, such as saccharides
and glycoproteins, play vital roles. However, saccharides and glycoproteins
in living systems usually exist in very low abundance, along with
abundant interfering components. High-efficiency detection of saccharides
and glycoproteins is a challenging yet highly impactful area of research.
Herein, we reported a novel magnetic microprobe with a benzoboroxole-modified
flexible multisite arm (PEG 2000-grafted PAMAM dendrimers; the microprobe
was denoted as BFMA-MNP) for high-efficiency saccharides detection.
The extraction capacity was significantly improved by ∼2 orders
of magnitude, because of the integration of the enhanced hydrophilicity
and multivalency effects in benzoboroxoles and the enhanced accessibility
of the binding sites within the PEG 2000-grafted PAMAM dendrimers.
As a result, the proposed approach possessed several advantages, compared
with previous boronic acid-based methods, including ultrahigh sensitivity
(limit of detection was <1 ng/mL), wide linear range (ranged from
0.5 μM to 2000 μM), and applicable in physiological pH
condition. Furthermore, we established a general BFMA-MNP/glycoproteins/AuNPs
sandwich assay to realize the visual glycoprotein qualitative screening
for the first time. The unique sandwich assay possessed the dual nature
of the magnetic separation by BFMA-MNPs and specific coloration by
citrate-coated AuNPs. This visual sandwich assay enabled fast differentiation
of the existence of glycoproteins in complicated samples without any
advanced instruments. We believe the proposed BFMA-MNP microprobe
herein will advance the ideas to detect and identify trace saccharides
and glycoproteins in important fields such as glycomics and glycoproteomics
In Situ Hydrothermally Grown TiO<sub>2</sub>@C Core–Shell Nanowire Coating for Highly Sensitive Solid Phase Microextraction of Polycyclic Aromatic Hydrocarbons
Nanostructured
materials have great potential for solid phase microextraction (SPME)
on account of their tiny size, distinct architectures and superior
physical and chemical properties. Herein, a core–shell TiO<sub>2</sub>@C fiber for SPME was successfully fabricated by the simple
hydrothermal reaction of a titanium wire and subsequent amorphous
carbon coating. The readily hydrothermal procedure afforded in situ
synthesis of TiO<sub>2</sub> nanowires on a titanium wire and provided
a desirable substrate for further coating of amorphous carbon. Benefiting
from the much larger surface area of subsequent TiO<sub>2</sub> and
good adsorption property of the amorphous carbon coating, the core–shell
TiO<sub>2</sub>@C fiber was utilized for the SPME device for the first
time and proved to have better performance in extraction of polycyclic
aromatic hydrocarbons. In comparison to the polydimethylsiloxane (PDMS)
and PDMS/divinylbenzene (DVB) fiber for commercial use, the TiO<sub>2</sub>@C fiber obtained gas chromatography responses 3–8
times higher than those obtained by the commercial 100 μm PDMS
and 1–9 times higher than those obtained by the 65 μm
PDMS/DVB fiber. Under the optimized extraction conditions, the low
detection limits were obtained in the range of 0.4–7.1 ng L<sup>–1</sup> with wider linearity in the range of 10–2000
ng L<sup>–1</sup>. Moreover, the fiber was successfully used
for the determination of polycyclic aromatic hydrocarbons in Pearl
River water, which demonstrated the applicability of the core–shell
TiO<sub>2</sub>@C fiber
Bioinspired Polyelectrolyte-Assembled Graphene-Oxide-Coated C18 Composite Solid-Phase Microextraction Fibers for In Vivo Monitoring of Acidic Pharmaceuticals in Fish
A novel solid-phase
microextraction (SPME) fiber was prepared by
gluing polyÂ(diallyldimethylammonium chloride) (PDDA) assembled graphene
oxide (GO)-coated C18 composite particles (C18@GO@PDDA) onto a quartz
fiber with polyaniline (PANI). The fiber surface coating was sequentially
modified with bioinspired polynorepinephrine, which provided a smooth
biointerface and makes the coating suitable for in vivo sampling.
The novel custom-made coating was used to extract acidic pharmaceuticals,
and high-performance liquid chromatography tandem mass spectrometry
(HPLC-MS/MS) was employed for analysis. The custom-made coating exhibited
a much higher extraction efficiency than the previously used commercial
polydimethylsiloxane (PDMS) and polyacrylate (PA) coatings. The custom-made
coating also possessed satisfactory stability (the relative standard
deviations (RSDs) ranged from 1.60% to 10.3% for six sampling-desorption
cycles), interfiber reproducibility (the RSDs ranged from 2.61% to
11.5%), and resistance to matrix effects. The custom-made fibers were
used to monitor the presence of acid pharmaceuticals in dorsal-epaxial
muscle of living fish, and satisfactory sensitivities (limits of detection
ranged from 0.13 ng/g to 7.56 ng/g) were achieved. The accuracies
were verified by the comparison with liquid extraction. Moreover,
the novel fibers were successfully used to monitor the presence of
acidic pharmaceuticals in living fish, which demonstrated that the
custom-made fibers were feasible for possible long-term in vivo continuous
pharmaceutical monitoring