This review begins with an overview of the appealing properties and various applications of gold nanoparticles, and briefly summarizes recent advances in using unmodified gold nanoparticles to detect different kinds o...This review begins with an overview of the appealing properties and various applications of gold nanoparticles, and briefly summarizes recent advances in using unmodified gold nanoparticles to detect different kinds of targets including nucleic acids, proteins, metal ions and small organic molecules. The key point to the unmodified gold nanoparticle-based visual detection assay is to control dispersion and aggregation of colloidal nanoparticles by targets of interest, which usually relies on affinities between gold nanoparticles and targets. The degree of dispersion or aggregation can be visualized through the change of the solution color or the precipitation of nanoparticles from the solution. Thus, the existence of the target molecules can be trans-lated into optical signals and monitored by the naked eye conveniently. Finally, some future prospects of this research field are given.展开更多
Rapid detection of foodborne pathogens is crucial to prevent the outbreaks of foodborne diseases.In this work,we proposed a novel microfluidic biosensor based on magnetorheological elastomer(MRE)and smartphone.First,m...Rapid detection of foodborne pathogens is crucial to prevent the outbreaks of foodborne diseases.In this work,we proposed a novel microfluidic biosensor based on magnetorheological elastomer(MRE)and smartphone.First,micropump and microvalves were constructed by deforming the MRE under magnetic actuation and integrated into the microfluidic biosensor for fluidic control.Then,the micropump was used to deliver immune porous gold@platinum nanocatalysts(Au@PtNCs),bacterial sample,and immunomagnetic nanoparticles(MNPs)into a micromixer,where they were mixed,incubated and magnetically separated to obtain the Au@PtNC-bacteria-MNP complexes.After 3,3',5,5'-tetramethylbenzidine and hydrogen peroxide were injected and catalyzed by the Au@PtNCs,smartphone was used to measure the color of the catalysate for quantitative analysis of target bacteria.Under optimal conditions,this biosensor could detect Salmonella typhimurium quantitatively and automatically in 1 h with a linear detection range of 8.0×10^(1) CFU/mL to 8.0×10^(4) CFU/mL and a detection limit of 62 CFU/mL.The microfluidic biosensor was compact in size,simple to use,and efficient for detection,and might be used for in-field screening of foodborne pathogens to prevent food poisoning.展开更多
A dual-amplification system is reported to apply in DNA sensing via the assembly of DNA and protein. In this process, the biotinylatedcapature DNA bounded with streptavidin（SA） through the biotinstreptavidin reactio...A dual-amplification system is reported to apply in DNA sensing via the assembly of DNA and protein. In this process, the biotinylatedcapature DNA bounded with streptavidin（SA） through the biotinstreptavidin reaction, and then the assembly of DNA and protein was triggered by the linker DNA after the target hybridized with biotinylatedcapature DNA. Sequentially, the 3,3＇,5,5＇-tetramethylbenzidine（TMB）was oxidized by H_2O_2 under the catalysis of horseradish peroxidase. Based on the variation of the color and the UV–vis absorbance intensities, qualitative and quantitative DNA analyses were realized. This proposed method could detect the target DNA as low as 1.75 pmol/L and discriminate perfectly matched target DNA from the mismatch DNA. What＇s more, it can be expanded to detect other molecules with a reasonable design of the corresponding DNA sequences.展开更多
A gold nanoparticle(AuNP)aggregation-induced colorimetric aptasensing method for quantitative detection of sulfadimethoxine(SDM)with a smartphone was developed.AuNPs were complexed with aptamers which protected Au NPs...A gold nanoparticle(AuNP)aggregation-induced colorimetric aptasensing method for quantitative detection of sulfadimethoxine(SDM)with a smartphone was developed.AuNPs were complexed with aptamers which protected Au NPs from aggregating in high-concentration salt solutions.In the presence of SDM,SDM bound with the aptamer on the surface of Au NPs with higher affinity,which competitively desorbed the aptamer from the AuNP surface and resulted in AuNPs aggregation,accompanied with a color change from red to purple-blue.The R,G and B values of images taken by a smartphone camera were analyzed with an app on the smartphone,and were utilized for quantitative analysis of SDM.Under the optimized conditions,the colorimetric aptasensing method using a smartphone showed high sensitivity for SDM,with the limit of detection of 0.023 ppm,lower than the allowed maximum SDM residue limit.This study provides a simple,fast,and easy to read method for on-site quantitative biochemical and cellular analysis.展开更多
Nanocrystalline cellulose is an amphiphilic, high surface area material that can be easily functionalized and is biocompatible and eco-friendly. It has been used singularly and in combination with other nanomaterials ...Nanocrystalline cellulose is an amphiphilic, high surface area material that can be easily functionalized and is biocompatible and eco-friendly. It has been used singularly and in combination with other nanomaterials to optimize biosensor design. The attachment of peptides and proteins to nanocrystalline cellulose and their proven retention of activity provide a route to bioactive conjugates useful in designs for point of care biosensors. Elastase is a biomarker for a number of inflammatory diseases including chronic wounds, and its rapid sensitive detection with a facile approach to sensing is of interest. An increased interest in the use of elastase sensors for point of care diagnosis is resulting in a variety of approaches to elsastase sensors utilizing different detection technologies. Here elastase substrate peptide-celluose conjugates synthesized as colorimetric and fluorescent sensors on cotton cellulose nanocrystals are compared. The structure of the sensor peptide-nanocellulose crystals when modeled with computational crystal structure parameters demonstrates the spatio-stoichiometric features of the nanocrystalline surface that allows ligand to active site protease interacttion. An understanding of the structure/function relations of enzyme and conjugate substrate of the peptides covalently attached to nancellulose has implications for enhancing the biomolecular transducer. The potential applications of both fluorescent and colorimetric detection to markers like elastase using peptide cotton cellulose nanocrystals as a transducer surface to model point of care biosensors for protease detection are discussed.展开更多
基金supported by the Ministry of Science and Technology(Grant Nos. 2009CB930000 and 2011CB933201)the National Natural Science Foundation of China (Grant Nos. 20890020, 21025520 and 90813032)+2 种基金the Chinese Academy of Sciences (Grant No. KJCX2-YW-M15)the Fundamental Research Funds for the Central Universities (Grant No.CDJXS10232211)the Ministry of Human Resources and Social Security of China
文摘This review begins with an overview of the appealing properties and various applications of gold nanoparticles, and briefly summarizes recent advances in using unmodified gold nanoparticles to detect different kinds of targets including nucleic acids, proteins, metal ions and small organic molecules. The key point to the unmodified gold nanoparticle-based visual detection assay is to control dispersion and aggregation of colloidal nanoparticles by targets of interest, which usually relies on affinities between gold nanoparticles and targets. The degree of dispersion or aggregation can be visualized through the change of the solution color or the precipitation of nanoparticles from the solution. Thus, the existence of the target molecules can be trans-lated into optical signals and monitored by the naked eye conveniently. Finally, some future prospects of this research field are given.
文摘Rapid detection of foodborne pathogens is crucial to prevent the outbreaks of foodborne diseases.In this work,we proposed a novel microfluidic biosensor based on magnetorheological elastomer(MRE)and smartphone.First,micropump and microvalves were constructed by deforming the MRE under magnetic actuation and integrated into the microfluidic biosensor for fluidic control.Then,the micropump was used to deliver immune porous gold@platinum nanocatalysts(Au@PtNCs),bacterial sample,and immunomagnetic nanoparticles(MNPs)into a micromixer,where they were mixed,incubated and magnetically separated to obtain the Au@PtNC-bacteria-MNP complexes.After 3,3',5,5'-tetramethylbenzidine and hydrogen peroxide were injected and catalyzed by the Au@PtNCs,smartphone was used to measure the color of the catalysate for quantitative analysis of target bacteria.Under optimal conditions,this biosensor could detect Salmonella typhimurium quantitatively and automatically in 1 h with a linear detection range of 8.0×10^(1) CFU/mL to 8.0×10^(4) CFU/mL and a detection limit of 62 CFU/mL.The microfluidic biosensor was compact in size,simple to use,and efficient for detection,and might be used for in-field screening of foodborne pathogens to prevent food poisoning.
基金supported by the National Science Foundation of China (No. 21205089)
文摘A dual-amplification system is reported to apply in DNA sensing via the assembly of DNA and protein. In this process, the biotinylatedcapature DNA bounded with streptavidin（SA） through the biotinstreptavidin reaction, and then the assembly of DNA and protein was triggered by the linker DNA after the target hybridized with biotinylatedcapature DNA. Sequentially, the 3,3＇,5,5＇-tetramethylbenzidine（TMB）was oxidized by H_2O_2 under the catalysis of horseradish peroxidase. Based on the variation of the color and the UV–vis absorbance intensities, qualitative and quantitative DNA analyses were realized. This proposed method could detect the target DNA as low as 1.75 pmol/L and discriminate perfectly matched target DNA from the mismatch DNA. What＇s more, it can be expanded to detect other molecules with a reasonable design of the corresponding DNA sequences.
基金the National Natural Science Foundation of China(Nos.21874098 and 61775157)Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi,Key R&D plan of Shanxi Province(International cooperation)(No.201903D421053)+3 种基金Key R&D Plan of Shanxi Province(high technologies field,No.201903D121158)the U.S.NSF(Nos.IIP2122712 and IIP 2052347)CPRIT(No.RP210165)DOT(No.CARTEEH)。
文摘A gold nanoparticle(AuNP)aggregation-induced colorimetric aptasensing method for quantitative detection of sulfadimethoxine(SDM)with a smartphone was developed.AuNPs were complexed with aptamers which protected Au NPs from aggregating in high-concentration salt solutions.In the presence of SDM,SDM bound with the aptamer on the surface of Au NPs with higher affinity,which competitively desorbed the aptamer from the AuNP surface and resulted in AuNPs aggregation,accompanied with a color change from red to purple-blue.The R,G and B values of images taken by a smartphone camera were analyzed with an app on the smartphone,and were utilized for quantitative analysis of SDM.Under the optimized conditions,the colorimetric aptasensing method using a smartphone showed high sensitivity for SDM,with the limit of detection of 0.023 ppm,lower than the allowed maximum SDM residue limit.This study provides a simple,fast,and easy to read method for on-site quantitative biochemical and cellular analysis.
文摘Nanocrystalline cellulose is an amphiphilic, high surface area material that can be easily functionalized and is biocompatible and eco-friendly. It has been used singularly and in combination with other nanomaterials to optimize biosensor design. The attachment of peptides and proteins to nanocrystalline cellulose and their proven retention of activity provide a route to bioactive conjugates useful in designs for point of care biosensors. Elastase is a biomarker for a number of inflammatory diseases including chronic wounds, and its rapid sensitive detection with a facile approach to sensing is of interest. An increased interest in the use of elastase sensors for point of care diagnosis is resulting in a variety of approaches to elsastase sensors utilizing different detection technologies. Here elastase substrate peptide-celluose conjugates synthesized as colorimetric and fluorescent sensors on cotton cellulose nanocrystals are compared. The structure of the sensor peptide-nanocellulose crystals when modeled with computational crystal structure parameters demonstrates the spatio-stoichiometric features of the nanocrystalline surface that allows ligand to active site protease interacttion. An understanding of the structure/function relations of enzyme and conjugate substrate of the peptides covalently attached to nancellulose has implications for enhancing the biomolecular transducer. The potential applications of both fluorescent and colorimetric detection to markers like elastase using peptide cotton cellulose nanocrystals as a transducer surface to model point of care biosensors for protease detection are discussed.
