A simple and sensitive method for determination of free amino acids in milk by microchip electrophoresis （MCE） coupled with laser-induced fluorescence （LIF） detection was developed. Seven kinds of standard amino a...A simple and sensitive method for determination of free amino acids in milk by microchip electrophoresis （MCE） coupled with laser-induced fluorescence （LIF） detection was developed. Seven kinds of standard amino ac- ids were derivated with sulfoindocyanine succinimidyl ester （Cy5） and then perfectly measured by MCE-LIF within 150 s. The parameters of MCE separation were carefully investigated to obtain the optimal conditions： 100 mmolo L^-1 sodium borate solution （pH 10.0） as running buffer solution, 0.8 kV as injection voltage, 2.2 kV as separation voltage etc. The linear range of the detection of amino acids was from 0.01 μmol·L^-1 to 1.0 μmol·L^-1 and the detection limit was as low as about 1.0 μmol·L^-1. This MCE-LIF method was applied to the measurements of free amino acids in actual milk samples and satisfactory experimental results were achieved.展开更多
Cytokine monitoring has attracted great attention due to its significance in the diagnosis and treatment of many diseases,such as tumors,microbial infections,and immunological diseases.Enzyme-linked immunosorbent assa...Cytokine monitoring has attracted great attention due to its significance in the diagnosis and treatment of many diseases,such as tumors,microbial infections,and immunological diseases.Enzyme-linked immunosorbent assay(ELISA)is one of the most popular methods in cytokine detection,ascribing to the lavish signal amplification methods in the ELISA platform.In addition to classical enzymes,other signal amplifiers such as fluorescent probes,artificial nano-enzymes,and photothermal reagents have been applied to reduce the detection limit and produce more sensitive ELISA kits.Due to the accumulative effect of heat,photothermal reagents are promising materials in the signal amplification of ELISA.However,the lack of efficient photothermal generation material at an aggregate scale may delay the further development of this area.In this contribution,based on an efficient organic photothermal aggregate material,an enzyme-free photothermally amplified fluorescent immunosorbent assay system consisting of an assay microfluidic chip and detecting platform was developed.The photothermal nanoparticles with highly efficient photothermal conversion by harvesting energy via excited-state intramolecular motions and enlarging molar absorptivity were successfully prepared.The detection concentration at 50 pg/mL of interleukin-2 was achieved,realizing a signal improvement of detection limits by 20-fold compared to that of previously reported photothermal ELISA.The microscopic imaging integrated with plane sweeping technology provided high spatial resolution and precision,indicating the potential of achieving high throughput profiling at the microscale.Moreover,as an alternative excitation source,light-emitting diode not only provided a more affordable and miniaturized detection system but also revealed the great feasibility of intramolecular motion-induced photothermy nanoparticles for biological analyses.展开更多
文摘A simple and sensitive method for determination of free amino acids in milk by microchip electrophoresis （MCE） coupled with laser-induced fluorescence （LIF） detection was developed. Seven kinds of standard amino ac- ids were derivated with sulfoindocyanine succinimidyl ester （Cy5） and then perfectly measured by MCE-LIF within 150 s. The parameters of MCE separation were carefully investigated to obtain the optimal conditions： 100 mmolo L^-1 sodium borate solution （pH 10.0） as running buffer solution, 0.8 kV as injection voltage, 2.2 kV as separation voltage etc. The linear range of the detection of amino acids was from 0.01 μmol·L^-1 to 1.0 μmol·L^-1 and the detection limit was as low as about 1.0 μmol·L^-1. This MCE-LIF method was applied to the measurements of free amino acids in actual milk samples and satisfactory experimental results were achieved.
基金Basic and Applied Basic Research Foundation of Guangdong Province,Grant/Award Number:2023A1515010702National Natural Science Foundation of China,Grant/Award Numbers:31870981,82020108016+2 种基金Innovation and Technology Commission,Grant/Award Number:ITC-CNERC14SC01Research Grants Council,University Grants Committee,Grant/Award Numbers:16306620,GRF 16209820STU Scientific Research Initiation Grant,Grant/Award Number:NTF22023。
文摘Cytokine monitoring has attracted great attention due to its significance in the diagnosis and treatment of many diseases,such as tumors,microbial infections,and immunological diseases.Enzyme-linked immunosorbent assay(ELISA)is one of the most popular methods in cytokine detection,ascribing to the lavish signal amplification methods in the ELISA platform.In addition to classical enzymes,other signal amplifiers such as fluorescent probes,artificial nano-enzymes,and photothermal reagents have been applied to reduce the detection limit and produce more sensitive ELISA kits.Due to the accumulative effect of heat,photothermal reagents are promising materials in the signal amplification of ELISA.However,the lack of efficient photothermal generation material at an aggregate scale may delay the further development of this area.In this contribution,based on an efficient organic photothermal aggregate material,an enzyme-free photothermally amplified fluorescent immunosorbent assay system consisting of an assay microfluidic chip and detecting platform was developed.The photothermal nanoparticles with highly efficient photothermal conversion by harvesting energy via excited-state intramolecular motions and enlarging molar absorptivity were successfully prepared.The detection concentration at 50 pg/mL of interleukin-2 was achieved,realizing a signal improvement of detection limits by 20-fold compared to that of previously reported photothermal ELISA.The microscopic imaging integrated with plane sweeping technology provided high spatial resolution and precision,indicating the potential of achieving high throughput profiling at the microscale.Moreover,as an alternative excitation source,light-emitting diode not only provided a more affordable and miniaturized detection system but also revealed the great feasibility of intramolecular motion-induced photothermy nanoparticles for biological analyses.
