17 research outputs found
Fully Reversible Ratiometric Nanosensors for Continuously Quantifying Mitochondrial Glutathione Concentration in Living Cells
No full textMitochondrial glutathione (mGSH) is both the cause of
the oxidative
damage and a mechanism for maintaining the redox homeostasis in mitochondria.
To effectively measure mGSH dynamics in living cells, we have developed
a new FRET-based nanosensor by immobilizing rhodamine B into dendritic
mesoporous silica nanoparticles and installing GSH probes and mitochondria-targeting
motifs onto the surface of nanoparticles. The result shows that these
nanosensors show efficient FRET and a full reversibility and rapid
response (<10 s) to GSH in the range of 0.5–20 mM, due to
their unique nanostructure and well-overlapped spectra. The excellent
photostability and low cytotoxicity make them an effective means for
monitoring mGSH concentration in real time. When the mGSH nanosensors
are used for quantitatively measuring mGSH variations under glucose
deprivation stimulation in HeLa cells, they successfully prove themselves
a useful tool for mitochondrial redox activity studies
Semiautomated Support Photoelectrochemical Immunosensing Platform for Portable and High-Throughput Immunoassay Based on Au Nanocrystal Decorated Specific Crystal Facets BiVO<sub>4</sub> Photoanode
No full textPhotoelectrochemical
(PEC) measurement has been developed rapidly
for bioanalysis in recent years. However, the actual application for
most existed PEC bioanalytical systems is still a challenge because
the perfect solutions for sensing surface design, high-throughput
detection, and portability are lacked. To successfully overcome these
limitations and realize accurate, continuous screening and assessing
on prognostic indicator of early stage cancer on the spot, an innovative
and portable semiautomated support power-free photoelectrochemical
(SP-PEC) immunosensing platform consisted with a miniature semiautomatic
injection system and digital multimeter (DMM) readout is designed
(prostate specific antigen, PSA, was used as the proof-of-concept
analyte). Decahedral BiVO<sub>4</sub> that decorated with Au nanocrystal
on {010} facets (Au-BiVO<sub>4</sub>) by photodeposition is used as
the photoanode materials to produce photocurrent signal under irradiation
of micro laser light (5.0 w, λ ≥ 380 nm). The monoclonal
anti-PSA capture antibody (mAb<sub>1</sub>)-functionalized Fe<sub>3</sub>O<sub>4</sub> magnetic nanobeads (mAb<sub>1</sub>-MN) and
glucose oxidase (GOx)/monoclonal detection antibody (mAb<sub>2</sub>)-conjugated gold nanoparticle (GOx-AuNP-mAb<sub>2</sub>) are employed
as immunosensing probe and signal probe, respectively. The H<sub>2</sub>O<sub>2</sub> as an excellent holes scavenger that in suit generated
from GOx oxidization glucose substrate significantly amplifies the
photocurrent. The variation of instantaneous current value that registered
as the signal of the immunoassay increases linearly with the logarithm
of target PSA concentration increasing in a wide range from 10 pg
mL<sup>–1</sup> to 100 ng mL<sup>–1</sup> with a low
detection limit (LOD) of 4.0 pg mL<sup>–1</sup>. The SP-PEC
immunosensing platform not only simplifies the assay process, but
also improves detecting efficiency. The semiautomatic and portable
SP-PEC analysis device allows analysis on spot and high-throughput
continuous detection. Additional, we also gain deep insight into the
relations between the specific shape as well as Au nanocrystal decoration
and PEC activity and speculate the possible enhancement mechanisms
of Au-BiVO<sub>4</sub>. Therefore, the present work not only develops
a flexible SP-PEC biosensor platform for rapid and continuous detection,
but also provides a possible route for designing high performance
photoelectric materials
