Research On The Rapid Detection Methods Of Organic Small Molecules Based On Pressure Signal Readout

With the development of science and technology and the deepening understanding of the biological functions of small molecules,higher requirements are put forward for the detection of organic small molecules,The current detection methods are basically based on optical,magnetic or electrochemical analysis methods,although these methods provide people with accurate detection results,but because of the need for precision large-scale instruments and professional operators,increasing the complexity of experiments and detection costs,limiting its promotion and application,so more urgent need for high sensitivity,fast and simple operation,low cost Small molecule detection tools or means.Pressure,a simple physical signal,can be detected by the common pressure gauge in daily life.As we all know,when the gas is generated and released from the solution,the volume expansion from the liquid to the gas can be achieved by 2³ orders of magnitude,resulting in a sudden increase of pressure in the closed system.In other words,the rapid detection strategy design of pressure signal based on gas production reaction,which has the function of signal amplification at the same time,will have a high analysis sensitivity.All in all,the rapid detection strategy based on the change of pressure signal,through simple pressure signal output,is easy to realize the miniaturization of analysis equipment,which provides a new idea for the development of portable detection tools and the realization of rapid field analysis.Based on the above understanding,in this paper,by inhibiting the significant pressure value change caused by catalytic gas production reaction as a signal probe,the antibiotic polymyxin?PMB?,the illegal additive Melamine?Mel?and the natural spermine?Spm?were taken as the research objects,and a new method for rapid detection of the above three organic small molecules was established by simply reading the pressure signal.The specific research contents are as follows:I pressure signal readout based on PtNPs catalytic activity inhibition was used to detect polymyxin B.Platinum nanoparticles?PtNPs?have the ability of catalyzing the decomposition of H₂O₂ into H₂O and O₂.The large amount of O₂ in the closed system can cause the increase of system pressure,and the pressure signal can be monitored by a simple digital manometer.When polymyxin B?PMB?exists,PMB plays a role of charge shielding and molecular bridging between PtNPs,which leads to the aggregation of PtNPs and the inhibition of catalytic activity.By examining the relationship between the change value of pressure signal??P?and PMB concentration in the presence of PMB,a fast PMB detection method based on pressure signal readout is constructed.The method has a good linear relationship in the range of 0.05?1.0mM,and the detection limit?3s?is 28.6 nM.The recovery of PMB in injection powder was 87.2%?102.3%and RSD was less than 5.9%.The recovery of PMB in urine was 88.2%?102.0%and RSD was less than 6.6%.This pressure signal reading strategy based on PtNPs catalytic activity inhibition provides a convenient new choice for the detection of PMB in pharmaceutical preparations and biological fluids,with the advantages of low cost and high sensitivity.?pressure signal readout based on Au@PtNPs catalytic activity inhibition is used for the rapid detection of Melamine in the field.The platinum coated gold nanoparticles?Au@PtNPs?,which are composed of 55 thymine oligonucleotide sequences?poly-55T?,have excellent catalytic activity and can catalyze the decomposition of H₂O₂ into H₂O and O₂,resulting in the increase of pressure in the closed system.The pressure signal can be monitored by a simple digital manometer.In the presence of Melamine?Mel?,poly-55t on the surface of Au@PtNPs forms triple hydrogen bond with Mel,which leads to the inhibition of Au@PtNPs aggregation catalytic activity.By examining the relationship between the change value of pressure signal??P?and Mel concentration in the presence of Mel,a rapid detection method of quantitative Mel based on pressure signal readout is constructed.The method has a good linear relationship in the range of 0.025?10.0mM,and the detection limit?3s?is 18.4nM.It was successfully used in the detection of milk powder samples,the recovery was in the range of 89.0%to 103.2%,and the relative standard deviation?RSD?was less than 6.6%.This pressure signal readout strategy based on Au@PtNPs catalytic activity inhibition provides a new method choice for Mel fast detection.?based on Au@PtNPs aggregation,the color and pressure dual signal readout is used for rapid detection of spermine.Platinum coated gold nanoparticles?Au@PtNPs?not only have the catalytic ability of platinum nanoparticles,but also have the chroma signal of gold nanoparticles.The adsorption of Au@PtNPs by oligonucleotide sequence?ssDNA?can be stable in high salt concentration.In the presence of spermine?Spm?,the double effects of charge shielding and ion bridging will lead to the aggregation of Au@PtNPs adsorbed by ssDNA,resulting in the simultaneous change of catalytic activity and solution color.Two kinds of signals adopt different detection methods.The pressure signal is detected by a simple digital manometer to detect the pressure signal change value??P?of the blank system and the sample adding system,and the chroma signal is detected by the ultraviolet spectrophotometer to measure the ratio value of Au@PtNPs absorbance(A_666nm/A_523nm)at the 666nm and 523nm peaks.Under the same Au@PtNPs concentration,the change value of pressure signal??P?has a linear relationship with the concentration of Spm in the range of0.01?1.6mM,and the detection limit?3s?is 9.2 nM,which has been successfully used in human urine detection.The recovery rate is between 90.5%and 102.6%,and the relative standard deviation?RSD?is less than 5.6%;the chroma signal(A_666nm/A_523nm)has a linear relationship with the concentration of Spm in the range of 0.08?0.6mM,and the detection limit?3s?is 16.8 nM.It was also successfully used in human urine and milk samples.The recovery was between 92.3%and 102.1%,and the relative standard deviation?RSD?was less than 3.9%.Compared with the traditional methods of chromatography and capillary electrophoresis,this rapid detection method based on dual signal with high sensitivity and rapid quantitative Spm can be used in both laboratory and non laboratory scenarios,The method described here will provide a convenient alternative and new idea for the detection of Spm in biological fluids and fermentation products.Based on the above results,we believe that it is of great significance to further understand the design of rapid detection strategy based on pressure signal readout,and further develop new portable detection tools to expand its application in environmental monitoring,food safety,health care and biomedical diagnosis.