Accurate detection of biomarkers is essential for disease diagnosis.Although the highly sensitive fluorescence probes are feasible for the above goal,it is typically interfered by the auto-fluorescence and light scatt...Accurate detection of biomarkers is essential for disease diagnosis.Although the highly sensitive fluorescence probes are feasible for the above goal,it is typically interfered by the auto-fluorescence and light scattering of the biological samples.Photochemical afterglow system(consisting of photosensitizer,afterglow substrate and emitter)based on cascade photochemical reactions exhibits long-lived luminescence(seconds to hours),thus avoiding background interference.With the assistance of polymers,such as polystyrene microspheres,the photochemical afterglow systems have been transformed into homogeneous and water-soluble nanoparticles,and used for in-vitro biomarker analysis.Here,we summarized the principle,preparation and applications of these afterglow nanoparticles,and evaluated their performance in clinical sample testing by comparing with other nanoparticle-based methods.Finally,several problems and possible solutions of afterglow nanoparticle-based methods in biomarker determination were also mentioned.展开更多
We review the recent progress of photonic generation of millimeter wave （MMW）-ultra-wideband （UWB） signals. To fully satisfy the standard defined by the Federal Communications Commission （FCC）, the baseband sign...We review the recent progress of photonic generation of millimeter wave （MMW）-ultra-wideband （UWB） signals. To fully satisfy the standard defined by the Federal Communications Commission （FCC）, the baseband signal （background signal） and the residual local oscillator （LO） signal should be well controlled. We discuss several schemes in this work for generating background-free MMW-UWB signals that are fully compliant with the FCC requirement.展开更多
The introduction of a double-chopping scheme eliminates the background level in the optical sampling system, where a Si avalanche photodiode acts as a two-photon absorber. We successfully demonstrate background-free o...The introduction of a double-chopping scheme eliminates the background level in the optical sampling system, where a Si avalanche photodiode acts as a two-photon absorber. We successfully demonstrate background-free optical sampling of 40-GHz and 160-GHz pulse trains.展开更多
In-situ monitoring of pesticide residues during crop growth or/and in related products is of great significance in avoiding the abuse of pesticides but remains challenging thus far.In this report,we proposed a backgro...In-situ monitoring of pesticide residues during crop growth or/and in related products is of great significance in avoiding the abuse of pesticides but remains challenging thus far.In this report,we proposed a background-free surface-enhanced Raman spectroscopy(bf-SERS)platform to non-destructively track the nitrile-bearing pesticide residues in soybean leaves with high sensitivity and selectivity.The outstanding feature of the assay stems from the dramatic Raman enhancement effect of the 50 nm-sized gold nanoparticles(AuNPs)towards the pesticides and simultaneously the background-free Raman signal of the nitrile group in the so-called Raman-silent region(1800-2800 cm^(-1)).This bf-SERS assay was applied to evaluate the penetration effects of nitrile-bearing pesticides and monitor their residues in soybean leaves after rinsing with various solutions,providing a reliable tool for guiding the safe use of nitrile-bearing pesticides in agriculture.展开更多
基金supported by the National Natural Science Foundation of China(No.22325403)the Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University,China(No.2022A02).
文摘Accurate detection of biomarkers is essential for disease diagnosis.Although the highly sensitive fluorescence probes are feasible for the above goal,it is typically interfered by the auto-fluorescence and light scattering of the biological samples.Photochemical afterglow system(consisting of photosensitizer,afterglow substrate and emitter)based on cascade photochemical reactions exhibits long-lived luminescence(seconds to hours),thus avoiding background interference.With the assistance of polymers,such as polystyrene microspheres,the photochemical afterglow systems have been transformed into homogeneous and water-soluble nanoparticles,and used for in-vitro biomarker analysis.Here,we summarized the principle,preparation and applications of these afterglow nanoparticles,and evaluated their performance in clinical sample testing by comparing with other nanoparticle-based methods.Finally,several problems and possible solutions of afterglow nanoparticle-based methods in biomarker determination were also mentioned.
基金supported in part by the National Natural Science Foundation of China(Nos.61377069,61431003,and 61335005)the National 863 Program of China(No.2015AA017002)the Beijing Nova Program
文摘We review the recent progress of photonic generation of millimeter wave （MMW）-ultra-wideband （UWB） signals. To fully satisfy the standard defined by the Federal Communications Commission （FCC）, the baseband signal （background signal） and the residual local oscillator （LO） signal should be well controlled. We discuss several schemes in this work for generating background-free MMW-UWB signals that are fully compliant with the FCC requirement.
文摘The introduction of a double-chopping scheme eliminates the background level in the optical sampling system, where a Si avalanche photodiode acts as a two-photon absorber. We successfully demonstrate background-free optical sampling of 40-GHz and 160-GHz pulse trains.
基金the support from the Shanxi Province Key R&D Plans(Nos.201903D211006-1 and 201803D221020-2)the Natural Science Foundation of Shanxi Province(No.201901D111225)+1 种基金the National Natural Science Foundation of China(Nos.21775075 and 21977053)the Fundamental Research Funds for the Central Universities,Nankai University(No.2122018165)。
文摘In-situ monitoring of pesticide residues during crop growth or/and in related products is of great significance in avoiding the abuse of pesticides but remains challenging thus far.In this report,we proposed a background-free surface-enhanced Raman spectroscopy(bf-SERS)platform to non-destructively track the nitrile-bearing pesticide residues in soybean leaves with high sensitivity and selectivity.The outstanding feature of the assay stems from the dramatic Raman enhancement effect of the 50 nm-sized gold nanoparticles(AuNPs)towards the pesticides and simultaneously the background-free Raman signal of the nitrile group in the so-called Raman-silent region(1800-2800 cm^(-1)).This bf-SERS assay was applied to evaluate the penetration effects of nitrile-bearing pesticides and monitor their residues in soybean leaves after rinsing with various solutions,providing a reliable tool for guiding the safe use of nitrile-bearing pesticides in agriculture.
