A miniature electrochemical detection system based on GOQDs/MWCNTs /SPCE* for determination the purine in cells

Evaluating the combined estrogenic effects of plant growth regulators via electrochemical and E-Screen methods

The study shows that plant growth regulators (PGRs) have estrogenic effects, which may disrupt the normal physiological functions of endogenous estrogen in organisms. This study used electrochemical methods to investigate the electrochemical behavior and estrogenic effects of PGRs gibberellic acid (GA3), ethylene (ETH), and naphthalene acetic acid (NAA) on estrogen-free human breast cancer cells (MCF-7) cells when exposed individually or in combination. The results indicate that GA3, ETH, and NAA, whether used alone or in combination, exhibit estrogenic effects on MCF-7 cells. The accuracy of the electrochemical method was validated against the E-Screen method, with consistent results between the two methods. Analysis of the combined estrogenic effects of PGRs detected by electrochemical and E-Screen methods revealed antagonistic effects for GA3/ETH, synergistic effects for GA3/NAA, additive effects for NAA/ETH, and synergistic effects for GA3/ETH/NAA. The combined estrogenic effects of PGRs at environmental actual concentration ratios detected by the electrochemical method were consistent with the results of the E-Screen method. This study successfully established a simple, fast, sensitive, and low-cost electrochemical detection method for the combined estrogenic effects of PGRs, providing a new approach for detecting such effects.

Electrochemistry detection of estrogenic effect: Regulation of de novo purine synthesis and catabolism by gibberellin and fulvestrant

The estrogenic effect of plant growth regulators has been received little attention, which leads to the lack of relevant toxicity data. In this study, the estrogenic effect induced by gibberellin with ERα-dependent manner was found by E-screen and western blot methods, and the electrochemical signals of MCF-7 cells regulated by gibberellin and fulvestrant were investigated. The results showed that the electrochemical signals of MCF-7 cells were increased by gibberellin, while reduced by fulvestrant significantly, and displayed an extremely sensitive response to the effects of estrogenic effect induced by ERα agonist and antagonist. Western blot results showed that the expressions of phosphoribosyl pyrophosphate amidotransferase and hypoxanthine nucleotide dehydrogenase in de novo purine synthesis and adenine deaminase in catabolism were more effective regulated by gibberellin and fulvestrant, resulting in significant changes of the levels of guanine, hypoxanthine and xanthine in cells, and then electrochemical signals. The results provide a theoretical basis for the establishment of new electrochemical detection method of the estrogenic effect of plant regulators.

Cytotoxicity and action mechanisms of polycyclic aromatic hydrocarbons by a miniature electrochemical detection system

The effects of six polycyclic aromatic hydrocarbons (PAHs) on the activity of V79 cells were studied by using a miniature electrochemical system based on graphene oxide quantum dots and multiwall carbon nanotubes modified anodized screen printed carbon electrode. The cytotoxicity sequence of PAHs on V79 cells was different with guanine/xanthine (G/X), adenine (A), hypoxanthine (HX), and the end product of purine nucleotide catabolism, uric acid (UA), as biomarkers. The IC₅₀ values measured with UA as the biomarker were the lowest, indicating that UA in cells was more sensitive to PAHs. The cytotoxicity sequence with G/X as the biomarker was the same as that of the MTT assay: pyrene > phenanthrene > benzo[a]pyrene > fluoranthene > fluorene > naphthalene. The cytotoxicity sequences measured by different biomarkers varied, which related to different structures that may influence the expression of the cellular aryl hydrocarbon receptor, gap junctional intercellular communication, and p53 protein. PAHs with different structures played varied roles in cell development and differentiation. Additionally, the electrochemical method was more sensitive than the MTT assay. The miniature electrochemical system enabled the simultaneous detection of four signals in cells, providing more information for multi-parameter evaluation and toxic mechanism study of PAHs and other pollutants.