2 research outputs found
Molecularly Imprinted Electrochemical Luminescence Sensor Based On Signal Amplification for Selective Determination of Trace Gibberellin A3
A new molecularly imprinted electrochemical luminescence
(MIP-ECL)
sensor was developed for Gibberellin A3 (GA3) determination. This
sensor is based on competitive binding between the GA3 and the Rhodamine
B (RhB)-labeled GA3 (RhB-GA3) to the MIP film. After the competitive
binding, the residual RhB-GA3 on the MIP was electro-oxidized to produce
RhB oxide, which could greatly amplify the weak electrochemiluminescence
(ECL) signal of luminol. The ECL intensity decreased when the RhB-GA3
was replaced by GA3 molecules in the samples. Accordingly, GA3 was
determined in the concentration range from 1 × 10<sup>–11</sup> to 3 × 10<sup>–9</sup> mol/L with a detection limit
of 3.45 × 10<sup>–12</sup> mol/L. The sensor shows high
sensitivity and selectivity, wide response range, good accuracy, and
fast response. Beer samples were assayed by using the sensors, and
the recoveries ranging from 96.0% to 103.2% were obtained
Low-Cost Fabrication of Paper-Based Microfluidic Devices by One-Step Plotting
In this technical note, we describe a facile method for
one-step fabrication of paper-based microfluidic devices, by simply
using commercially available permanent markers and metal templates
with specific patterns. The fabrication process involves only a single
step of plotting pattern in paper; it can be typically finished within
1 min. The ink marks formed in the patterned paper will act as the
hydrophobic barriers to define the hydrophilic flow paths or separate
test zones. Various paper devices can be created by using different
templates with corresponding patterns. Transparent adhesive tape-sandwiched
devices could protect their assay surfaces from potential contamination.
In the proof-of-concept experiments, circular paper test zones (∼3
mm diameter) were fabricated for colorimetric and quantification detection
of prostate-specific antigen (PSA) as a model target, based on dot-immunogold
staining assays coupled with gold enhancement amplification. Several
serum specimens were additionally evaluated with this new approach
and the results were compared with the commercial chemiluminescence
immunoassay, validating its feasibility of practical applications.
Such a one-step plotting method for paper patterning does not require
any specialized equipments and skills, is quite inexpensive and rapid,
and thus holds great potential to find wide applications especially
in remote regions and resource-limited environments such as small
laboratories and private clinics