A bulged-type enzyme-free recognition strategy designed for single nucleotide polymorphisms integrating with label-free electrochemical biosensor.

Compared to conventional nucleic acid detection methods, label-free single nucleotide polymorphism (SNP) detection presents challenging due to the necessity of discerning single base mismatches, especially in the field of enzyme-free detection. In this study, we introduce a novel bulged-type DNA duplex probe designed to significantly amplify single-base differences. This probe is integrated with programmable DNA-based nanostructures to develop a sensitive, label-free biosensor for nonenzymatic SNP detection.

A SERS-Based Dual-Parameter Monitoring Nanoprobe of ROS and PI3K/Akt during Ginsenoside Rg3-Induced Cell Apoptosis.

Both the reactive oxygen species (ROS) level and Phosphatidylinositol 3 Kinase (PI3K) protein content are two crucial parameters for characterizing states of cell apoptosis. Current methods measure these parameters with two different techniques, respectively, which usually lead to evaluation contingency. Ginsenoside Rg3 exhibits an excellent anticancer effect, which is enacted by the Phosphatidylinositol 3 Kinase/Protein Kinase B (PI3K/Akt) pathway involving ROS; however, the precise mechanism that induces cell apoptosis remains unknown.

SERS-based error calibration of a TMB-HO colorimetric system.

3,3',5,5'-tetramethylbenzidine (TMB)-HO is widely used as an effective colorimetric system, in which the color reaction is implemented with peroxidase-catalyzed TMB oxidation by HO that usually measured UV-vis absorption spectra or Raman spectra. However, its low accuracy significantly limits its application. Blue charge transfer complex (CTC), which is the product of TMB and HO reaction and is used as the basis for partial colorimetric methods, usually causes colorimetric error owing to changes in the UV-vis absorption and Raman spectra during TMB oxidation under various environmental conditions (catalyst type, temperature, HO concentration).

Colorimetry /SERS dual-sensor of HO constructed via TMB-FeO@ AuNPs.

Hydrogen peroxide (HO) detection with high sensitivity plays an important role in biomedical research and food engineering. By combining colorimetry and surface enhanced Raman spectroscopy (SERS), we synthetize a novel HO dual-sensor constructed via TMB-FeO@AuNPs. In the presence of HO, the peroxide model enzyme might catalyze the oxidation of 3,3',5,5'- tetramethylbenzidine (TMB) as blue charge transfer complex (CTC) for colorimetry, and then facilitate the sensitivity improvement of SERS detection.

Au/Ag composite-based SERS nanoprobe of Cr.

Quantitative characterization of Cr, an important element revealing human metabolism and biological environmental variation, is still difficult to achieve by conventional biochemical methods due to the lack of high-sensitivity, real-time techniques with rapid response detection. Using surface-enhanced Raman scattering (SERS), we construct an Au/Ag composite-based SERS nanoprobe for the quantitative characterization of Cr content in solution, in which DL-mercaptosuccinic acid (DL-MSA) is employed for Raman signal enhancement, and 4-mercaptobenzoic acid (4-MBA) is chosen as the Raman reporter. The achieved result demonstrates obvious advantages of the synthesized Au/Ag composite-based SERS nanoprobe in sensitivity and response speed.

Receptor-mediated photothermal/photodynamic synergistic anticancer nanodrugs with SERS tracing function.

Phototherapy, especially the photothermal therapy (PTT) and the photodynamic therapy (PDT), have become very promising in cancer treatment due to its low invasiveness and high efficacy. Both PTT and PDT involve the utilization of light energy, and their synergistic treatment should be a good solution for cancer treatment by ingenious design. The therapeutic effect of phototherapy is closely associated with the amount and location of anticancer-nanodrugs accumulated in tumor cells, and the receptor-mediated endocytosis should be an excellent candidate for enhancing anticancer-nanodrugs internalization.

Dynamic monitoring and quantitative characterization of intracellular HO content by using SERS based boric acid nanoprobe.

Quantitative characterization of intracellular HO content, which is still difficult by the conventional biochemical methods due to the lack of real-time and non-invasive technique of single cell measurement, is a useful solution for cell state assessment. Based on the surface enhanced Raman scattering (SERS), we construct a novel boric acid (BA) nanoprobe to perform quantitative characterization of HO content, in which the p-thiol benzene boric acid (4-MPBA) reporter molecule modified with gold nanorods (AuNRs) is employed for Raman signal enhancement. The achieved result demonstrates obvious advantages of the synthesized AuNRs/4-MPBA/BA nanoprobe in measurement sensitivity of HO content.

Study on the precise mechanism of Mitoxantrone-induced Jurkat cell apoptosis using surface enhanced Raman scattering.

Mitoxantrone (MTX), one representative of anthraquinone ring anticancer drugs, reveals excellent anticancer effects in acute leukemia. Though current studies have shown that MTX-induced acute leukemia cell apoptosis is implemented by inserting into DNA, and then leading to DNA breakage and the subsequent transcription termination, but the specific location information of MTX embedded in DNA remains unknown. In this study, combining surface enhanced Raman scattering (SERS) and principal component analysis (PCA), we achieve the biochemical changes of MTX-induced Jurkat cell apoptosis and the location information of MTX embedded in DNA.

Raman spectrum spectral imaging revealing the molecular mechanism of Berberine-induced Jurkat cell apoptosis and the receptor-mediated Berberine delivery system.

Berberine (BBR), a traditional Chinese herb extract medicine, reveals some anticancer effects in leukemia, but it remains controversial about the molecular mechanism of BBR-induced leukemia cell apoptosis. In this study, combining Raman spectrum and spectral imaging, both the biochemical changes of BBR-induced Jurkat cell apoptosis and the precise distribution of BBR in single cell are presented. In contrast, we also show the corresponding results of Jatrorrhizine (JTZ) and Palmatine (PMT), two structural analogues of BBR.