Inhibitory Activity of Prunus mume,Copitis chinensis and Crataegus pinnatifida on Vibrio harveyi and Its Biofilm

[Objective] This study was conducted to determine the in-vitro inhibitory effects of Prunus mume,Coptis chinensis and Crataegus pinnatifida on Vibrio harveyi and its biofilm. [Method]The inhibitory zone diameters of the three Chinese herbal medicines against V. harveyi were determined by agar diffusion method; the minimal inhibitory concentration( MIC) and minimal bactericidal concentration( MBC) values of the three Chinese herbal medicines against V. harveyi were determined by doubling dilution method; and the effects of the three Chinese herbal medicines on the formation of V. harveyi biofilm were determined by methyl thiazolyl tetrazolium( MTT) method. [Result]The three Chinese herbal medicines all inhibited V. harveyi to different degrees. C. chinensis and C. pinnatifida and P. mume exhibited the inhibitory zone diameters of( 17. 62 ± 0. 04),( 20. 16 ± 0. 08) and( 30. 76 ± 0. 26) mm against V. harveyi,respectively. P. mume and C. pinnatifida had strong inhibitory effects on V. harveyi. The MIC and MBC values of P. mume against V. harveyi were 7. 812 5 mg/ml; the MIC and MBC values of C. pinnatifida against V. harveyi were 31. 25 mg/ml; and the MIC and MBC values of C. chinensis against V. harveyi were 62. 5 mg/ml. P. mume had the strongest antibacterial and bactericidal ability. The MIC values of C. pinnatifida,C. chinensis and P. mume against V. harveyi were 7. 81,7. 81 and 1. 96 mg/ml,respectively,i. e.,P. mume exhibited the lowest MIC. [Conclusion] P. mume,C. pinnatifida and C. chinensis all have inhibitory effects on V. harveyi and its biofilm,and P. mume has the strongest bactericidal ability.

Low-temperature optothermal nanotweezers

Optical tweezers that rely on laser irradiation to capture and manipulate nanoparticles have provided powerful tools for biological and biochemistry studies.However,the existence of optical diffraction-limit and the thermal damage caused by high laser power hinder the wider application of optical tweezers in the biological field.For the past decade,the emergence of optothermal tweezers has solved the above problems to a certain extent,while the auxiliary agents used in optothermal tweezers still limit their biocompatibility.Here,we report a kind of nanotweezers based on the sign transformation of the thermophoresis coefficient of colloidal particles in low-temperature environment.Using a self-made microfluidic refrigerator to reduce the ambient temperature to around 0℃in the microfluidic cell,we can control a single nanoparticle at lower laser power without adding additional agent solute in the solution.This novel optical tweezering scheme has provided a new path for the manipulation of inorganic nanoparticles as well as biological particles.

Advances in inorganic nanoparticles trapping stiffness measurement:A promising tool for energy and environmental study

Optical tweezers system has emerged as an efficient tool to manipulate tiny particles in a non-invasive way.Trapping stiffness,as an essential parameter of an optical potential well,represents the trapping stability.Additionally,trapping inorganic nanoparticles such as metallic nanoparticles or other functionalized inorganic nanoparticles is important due to their properties of good stability,high conductivity,tolerable toxicity,etc.,which makes it an ideal detection strategy for bio-sensing,force calculation,and determination of particle and environmental properties.However,the trapping stiffness measurement(TSM)methods of inorganic nanoparticles have rarely been analyzed and summarized.Here,in this review,the principle and methods of TSM are analyzed.We also systematically summarize the progress in acquiring inorganic particles trapping stiffness and its promising applications.In addition,we provide prospects of the energy and environment applications of optical tweezering technique and TSM.Finally,the challenges and future directions of achieving the nanoparticles trapping stiffness are discussed.

CRISPR-powered optothermal nanotweezers:Diverse bio-nanoparticle manipulation and single nucleotide identification

Optothermal nanotweezers have emerged as an innovative optical manipulation technique in the past decade,which revolutionized classical optical manipulation by efficiently capturing a broader range of nanoparticles.However,the optothermal temperature field was merely employed for in-situ manipulation of nanoparticles,its potential for identifying bio-nanoparticles remains largely untapped.Hence,based on the synergistic effect of optothermal manipulation and CRIPSR-based bio-detection,we developed CRISPR-powered optothermal nanotweezers(CRONT).Specifically,by harnessing diffusiophoresis and thermo-osmotic flows near the substrate upon optothermal excitation,we successfully trapped and enriched DNA functionalized gold nanoparticles,CRISPR-associated proteins,as well as DNA strands.Remarkably,we built an optothermal scheme for enhancing CRISPR-based single-nucleotide polymorphism(SNP)detection at single molecule level,while also introducing a novel CRISPR methodology for observing nucleotide cleavage.Therefore,this innovative approach has endowed optical tweezers with DNA identification ability in aqueous solution which was unattainable before.With its high specificity and feasibility for in-situ bio-nanoparticle manipulation and identification,CRONT will become a universal tool in point-of-care diagnosis,biophotonics,and bio-nanotechnology.