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The application of the digital plotter offered a cost-effective and more reproducible method for preparation of disposable working electrodes, which might be extended for other biochemical assays.Functional DNAs-functionalized magnetic beads (MBs) offer great potential in bioanalysis field because of their target recognition and magnetic separation functions. However, the recognition capability and hybridization affinity of DNA probes often suffer from limited available space, poor probe conformation and non-selective adsorption. To overcome these limitations, we herein used aptamer-pendant DNA tetrahedron nanostructure-functionalized MBs (TETapt-tet MBs) to develop a target-response fluorescence method with tetracycline (TET) as a model. In the absence of TET, 6-carboxy-X-rhodamine-labeled complementary DNAs (ROX-cDNAs) were assembled on the surface of MBs. Upon the addition of target TET, the ROX-cDNAs were separated and released from the MBs to generate fluorescence signal. The limit of detection and limit of quantification for TET were found to be 6 pg mL-1 and 20 pg mL-1, respectively. Compared with ssDNA-functionalized MBs surface, the designed DNA tetrahedron nanostructure-based surface could decrease the hybridization time and reduce false positives, ensuring the accuracy of TET detection in complex samples. The presented method was successfully employed for TET detection in honey samples. Moreover, this functionalization strategy could be extended to detect multiple antibiotics by simply substituting different aptamer sequences. Therefore, the proposed method has great potential in the field of food safety and public health.Adenosine has received great attentions acting as a potential biomarker for monitoring lung cancer. Most of the reported studies for adenosine detection require large instruments and complicated procedures. Herein, a sensitive, rapid and in-situ colorimetric aptasensor was developed for adenosine detection. Moreover, a homemade biomimetic electronic-eye (E-eye) was established and utilized as a portable in-time detection equipment. The entire measurement can be completed within 20 min, including the combination of aptamer with adenosine or AuNPs and the detection of adenosine. Four different kinds of aptamer were compared and the results showed that the AuNPs-aptamer-biotin system was the most stable and with the widest detection range of 5.0 μM-60.0 μM and the lowest LOD of 0.17 μM. Moreover, the artificial urine samples were also tested with a linear range from 5.0 to 50.0 μM and a LOD of 0.48 μM. The results validated that the aptasensor together with the E-eye can be a promising platform for adenosine detection.In this study, a fluorescent aptasensor is described for ultrasensitive detection of prostate-specific antigen (PSA) using DNA triangular prism as a platform for attachment of fluorophore (PicoGreen, PG), streptavidin magnetic beads (SMBs) and RecJf exonuclease as enhancers of fluorescence difference between presence and absence of target. Presence of PSA leads to the formation of the DNA origami. So, a strong fluorescence is observed following the addition of PG. while, the DNA triangular prism cannot be formed in the lack of target. Thus, a very weak fluorescence can be measured after addition of PG. The proposed biosensor indicated high selectivity, a broad linear range from 200 pg/mL to 300 ng/mL and a very low detection limit of 30 pg/mL for PSA. Applying the designed aptasensor, PSA was successfully detected in human serum samples. This work provides a new way for detection of biomarkers in clinical samples.Eicosanoids derived from n-6 and n-3 polyunsaturated fatty acids (PUFAs), serving as important signaling molecules, are implicated in many physiological and pathological processes, including Type 2 diabetes mellitus (T2DM). However, the quantification of endogenous eicosanoids is challenged by high structural similarity, low abundance in biological sample and poor electrospray ionization efficiency. In the current study, a sensitive and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to quantify 65 eicosanoids derived from n-6 and n-3 PUFAs in plasma samples using twin derivatization strategy with a pair of reagents, 5-(dimethylamino) naphthalene-1-sulfonyl piperazine (Dns-PP) and (diethylamino) naphthalene-1-sulfonyl piperazine (Dens-PP). Dns-PP-derivatized plasma sample was mixed with the equal volume of Dens-PP-derivatized eicosanoid internal standards for LC-MS/MS analysis in multiple reaction monitoring (MRM) mode. After Dns-PP derivatization, the ionization effici pathogenesis of T2DM and other diseases.In the present study, a novel plasmonic sensing platform was proposed for sequential colorimetric detection of dopamine (DA) and glutathione (GSH) in human serum sample by taking advantage of plasmon hybridization in graphene nanoribbons/sliver nanoparticles (GNR/Ag NPs) hybrid. DA was detected based on etching strategy and morphology transition of label-free Ag NPs hybridized with GNR. As a result of the etching process, hexagonal Ag NPs were changed to smaller corner-truncated nanoparticles and a blue shift was observed in its plasmonic band, accompanied by the color change from green to red. Sequentially, GSH induced aggregation of Ag NPs which resulted in a decrease in absorption intensity of Ag NPs plasmonic band and a color change from red to gray. Tacrolimus By employing GNR/Ag NPs hybrid as a sensitive colorimetric sensor, DA and GSH were successfully detected in low concentrations of 0.04 μM and 0.23 μM, respectively. The same experiment was carried out in the absence of GNR and the detection limits were obtained 0.46 and 1.2 μM for DA and GSH, respectively. These results confirmed the effective role of GNR on the sensitivity improvement of GNR/Ag NPs hybrid. The proposed simple and sensitive sensing approach offered a beneficial and promising platform for sequential detection of DA and GSH in the biological samples.Beta-lactoglobulin is a natural milk protein and the main cause of infant milk allergy. In this work, a sensitive, selective and inexpensive electrochemical biosensor for the detection of β-lactoglobulin was developed. In this sensor, a DNA aptamer was used instead of an expensive antibody as the recognition group highly selective for β-lactoglobulin. The flower-like BiVO4 microspheres were firstly found to have peroxidase mimic catalytic activity and used to amplify the electrochemical signal. The aptamer can bind β-lactoglobulin and fall off from the working electrode, after which the DNA2/Au/BiVO4 probe can be fixed to the DNA1/AuNPs/ITO working electrode by the hybridization of DNA2 with DNA1. Therefore, a higher concentration of β-lactoglobulin leads to increased fabrication of the DNA2/Au/BiVO4 probe on the surface of the working electrode, and thereby increases the electrochemical signal. This electrochemical biosensor exhibited a wide detection range from 0.01 to 1000 ng mL-1, with a limit of detection (LOD) of 0.