[background]
As we all know, hydrogen sulfide (H2S) is an important gas transporter in living organisms, which plays an important role in regulating cell growth, anti-inflammatory and a series of biological processes. It is found that the abnormal regulation of H2S is related to diabetes, cirrhosis and other diseases. Therefore, it is very important to develop an accurate method to monitor H2S in biological system. At present, electrochemical analysis, surface enhanced Raman scattering and other methods have been developed to detect and track H2S in biological systems. Although significant progress has been made, there are still some key problems to be solved, such as low sensitivity, living cell quantification, specimen destruction and phototoxicity. Another special challenge is that when the concentration of H2S is higher than that in complex biological system, it will be interfered by chemicals such as glutathione (GSH). Therefore, it is very important to develop a strategy that can detect H2S with high sensitivity and selectivity in complex biological systems. In addition, circular dichroism (CD) spectrum is an ideal and powerful biological detection and analysis technology, because it can be used for non-destructive cell analysis with high sensitivity.
[achievement introduction]
Based on this, Professor Xu Ligang (corresponding author) of Jiangnan University reported a cuxos @ zif-8 nanostructure probe, which can be used to energy the living cells and the level of hydrogen sulfide (H2S) in vivo. Zeolites imidazolium skeleton-8 (zif-8) was used as the encapsulation shell to improve the selectivity of the probe. It has been found that this unique nanostructure can successfully realize the hypersensitive quantification and biological imaging of H2S in living cells. Among them, the detection limits of CD and fluorescence mode are 0.8 and 5.3 nmol per 106 cells, respectively. At the same time, it is found that the conversion of chiral cuxos NPs to non chiral CuxS NPs is helpful to achieve ultra sensitive detection. In addition, the probe can also be used to detect and track the level of H2S in tumor bearing animals. All in all, these findings provide a new idea for the establishment of clinical quantitative tracking and analysis platform. The research results were published in adv. mater., a famous international journal, entitled "central cuxos @ zif-8 nanostructures for ultra sensitive quantification of hydrogen sulfide in vivo".
[text interpretation]
Figure 1. Characterization of cuxos-cy3 @ zif-8 nanoprobe
(A) TEM image of cuxos-cy3; (b) TEM image of cuxos-cy3 @ zif-8; (c) EDS mapping image of cuxos-cy3 @ zif-8; (d) X-ray photoelectron spectroscopy of cuxos-cy3.
Figure 2. Characterization of the nanoprobe after reaction with Na2S
CD and fluorescence spectra of cuxos-cy3 @ zif-8 probe before and after the reaction of (a-b) with Na2S; (C-D) Cu and s X-ray photoelectron spectra of cuxos-cy3 after the addition of Na2S.
Figure 3. Cuxos-cy3 @ zif-8 nanoprobe detects H2S based on CD and FL dual modes
(A) The results show that the nanoprobe has response to different Na2S (the donor of H2S); (b) the linear relationship between the concentration of Na2S and the intensity of corresponding Δ CD (Δ CD = cd488-cd560); (c) the fluorescence spectrum of cuxos-cy3 @ zif-8 reacting with different Na2S; (d) the standard curve of 560 nm fluorescence peak intensity under different Na2S concentrations.
Figure 4. Detection of H2S in living cells based on CD and FL dual modes
(A) HeLa cells pretreated with cuxos-cy3 @ zif-8 have confocal images of their reactions with different concentrations of H2S; (b) the standard curve of H2S corresponds to the emission fluorescence ratio (i560 / i450); (c) the Δ CD value (Δ CD = cd488-cd560) of HeLa cells pretreated with different H2S treatments and then with probes; (d) the Δ CD value is a function of the concentration of H2S.
Figure 5. Application of cuxos @ zif-8 nanoprobe in mice
(A) The confocal images of pcs-460-010 cells, MCF-7 cells and HeLa cells with the probe; (b) using cuxos-cy3 @ zif-8 nanoprobe to image the endogenous H2S in the tumor bearing mice model.
[summary]
To sum up, a new nanostructure, cuxos @ zif-8 nanoprobe, has been designed, which can detect H2S with super sensitivity and selectivity. The probe can detect H2S not only in vitro, but also in living cells and in vivo. The experimental results show that when the chiral cuxos is converted into the non chiral cuxos, it is helpful to realize the hypersensitivity detection. All in all, this method has opened up a new way for the research of chiral nanostructures in the fields of biocatalysis, bio imaging and life science diagnosis.
Literature link: central cuxos @ zif-8 nanostructures for ultra sensitive quantification of hydrogen sulfide in vivo. (adv. mater., 2020, DOI: 10.1002/adma.201906580). This paper is contributed by CQR. Submission email
Contribution and content cooperation of tougao@cailiaoren.com can be added with wechat cailiaorenvip