There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Applications in Theranostics Guanying Chen,*,†,‡ Hailong Qiu,†,‡ Paras N. Prasad,*,‡,§ and Xiaoyuan Chen* †School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China ‡Department of Chemistry and the Institute for Lasers, Photonics, and Biophotonics, University at Buffalo, State University of New York, Buffalo, New York 14260, United States Department of Chemistry, Korea University, Seoul 136-701, Korea Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892-2281, United States

Upconversion Nanoparticles: Design, Nanochemistry, and Applications in Theranostics

Upconversion luminescent materials: advances and applications.

Recent development in 2D materials beyond graphene

Luminescent sensors based on metal-organic frameworks

Realization of highly responsivity UV detectors is a critical challenge for accelerating the application of UV detectors. Exploiting nanoplasmonic enhancement, Ag nanoparticles have been formed on the GaN surface and the responsivity of the GaN UV detector has been enhanced about 30 times compared with that without Ag nanoparticles.

Realization of a high-performance GaN UV detector by nanoplasmonic enhancement

An optical sensor for Cu(II) detection with upconverting luminescent nanoparticles as an excitation source

A promising strategy using bimetallic Tb/Eu-MOFs as a fluorescence ratio sensor for Bacillus anthracis detection is reported in this work. The nanostructured Tb/Eu-MOFs have been synthesized through rapid and direct precipitation at room temperature. The energy transfer from Tb3+ to Eu3+ in this system is observed and studied. As a unique biomarker of Bacillus anthracis, dipicolinic acid (DPA) can readily combine with Tb3+ by replacing the coordinated water and enhance the green fluorescence emission of the MOF. The bimetallic MOF possesses two luminescent centers in one system, which can facilitate self-calibration without the requirement for any instrument-specific calibration. More interestingly, after introducing the appropriate concentration of DPA, the emission color of Tb/Eu(BTC) changes from red-orange to yellow-green, which can be observed by the naked eye. This luminescence color variation is caused by the transformation of the energy transfer process in the MOF. The nano-sized bimetallic Tb/Eu-MOFs is further employed to detect DPA in human serum and the results are in agreement with their standard additions in an acceptable recovery range. The combined merits of high selectivity, good reproducibility, rapid and naked-eye recognition of DPA make Tb/Eu(BTC) a promising material for application in the convenient detection of Bacillus anthracis.

A nanoscaled lanthanide metal–organic framework as a colorimetric fluorescence sensor for dipicolinic acid based on modulating energy transfer

A novel fluorescent chemosensor based on rhodamine derivative (Rh1) has been designed and synthesized for detection of Hg2+ ions, which exhibits high sensitivity and selectivity over other metal ions in aqueous solution and living cells. Moreover, this “Off–On”-type fluorescent sensor could successfully mimic a molecular level keypad lock in the presence of Cu2+ ions. Stimulated by the two chemical inputs (Hg2+ and Cu2+), Rh1 undergoes transformation of the structure between spirocyclic and ring-opened spirocyclic, which results in the change of fluorescence. Significantly, the outputs of the system depend on not only the proper combination but also on the correct order of the input signals, which is the most important feature of the keypad lock system. Only a specific sequence of inputs, i.e. the correct password, results in strong fluorescence emission at 555 nm which can be used to “open” this molecular keypad lock. Therefore, this molecular keypad lock has the potential for application in security devices, which could be used to authorize a user, to verify authentication of a product, or to initiate a higher process.

A cell compatible fluorescent chemosensor for Hg2+ based on a novel rhodamine derivative that works as a molecular keypad lock

The tunability of surface plasmon resonance can enable the highest degree of localised surface plasmon enhancement to be achieved, based on the emitting or absorbing wavelength. In this article, tunable dipole surface plasmon resonances of Ag nanoparticles (NPs) are realized by modification of the SiO2 dielectric layer thicknesses. SiO2 layers both beneath and over the Ag NPs affected the resonance wavelengths of local surface plasmons (LSPs). By adjusting the SiO2 thickness beneath the Ag NPs from 5 nm to 20 nm, the dipole surface plasmon resonances shifted from 470 nm to 410 nm. Meanwhile, after sandwiching the Ag NPs by growing SiO2 before NPs fabrication and then overcoating the NPs with various SiO2 thicknesses from 5 nm to 20 nm, the dipole surface plasmon resonances changed from 450 nm to 490 nm. The SiO2 cladding dielectric layer can tune the Ag NP surface charge, leading to a change in the effective permittivity of the surrounding medium and thus to a blueshift or redshift of the resonance wavelength. Also, the quadrupole plasmon resonances were suppressed by the SiO2 cladding layer because the dielectric SiO2 can suppress level splitting of surface plasmon resonances caused by the Ag NP coupling effect.

/pdf/tunable-dipole-surface-plasmon-resonances-of-silver-1fesextv9v.pdf

Hong Jiang

Papers

Realization of a high-performance GaN UV detector by nanoplasmonic enhancement

An optical sensor for Cu(II) detection with upconverting luminescent nanoparticles as an excitation source

A nanoscaled lanthanide metal–organic framework as a colorimetric fluorescence sensor for dipicolinic acid based on modulating energy transfer

A cell compatible fluorescent chemosensor for Hg2+ based on a novel rhodamine derivative that works as a molecular keypad lock

Tunable Dipole Surface Plasmon Resonances of Silver Nanoparticles by Cladding Dielectric Layers