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A photovoltaic photodetector harnessing near infrared band gap absorption by thin films of post-synthetically sorted semiconducting single walled carbon nanotubes (s-SWCNTs) is described. Peak specific detectivity of 6×10¹¹ Jones at -0.1 V bias at 1210 nm is achieved using a heterojunction device architecture: indium tin oxide/ ca. 5 nm s-SWCNT / 120 nm C₆₀ / 10 nm 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) / Ag. The photodiodes are characterized by a series resistance of 2.9 Ω cm² and a rectification ratio of 10⁴ at ±1V. These results are expected to guide the exploration of new classes of solution-processable, mechanically flexible, integrable, thin film photovoltaic photodetectors with tunable sensitivity in the visible and infrared spectra based on semiconducting carbon nanotubes.

A design strategy for (porphinato)zinc-based fluorophores that possess large near infrared fluorescence quantum yields is described. These fluorophores are based on a (5,15-diethynylporphinato)zinc(II) framework and feature symmetric donor or acceptor units appended at the meso-ethynyl positions via benzo[c][1,2,5]thiadiazole moieties. These (5,15-bis(benzo[c][1′,2′,5′]thiadiazol-4′-ylethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (4), (5,15-bis[4′-(N,N-dihexylamino) benzo[c][1′,2′,5′]thiadiazol-7′-ylethynyl]-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (5), (5,15-bis([7′-(4″-n-dodecyloxyphenylethynyl)benzo[c][1′,2′,5′]thiadiazol-4′-yl]ethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (6), (5,15-bis([7′-([7″-(4″ ′-n-dodecyloxyphenyl)benzo[c][1″,2″,5″]thiadiazol-4″-yl]ethynyl)benzo[c][1′,2′,5′]thiadiazol-4′-yl]ethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (7), 5,15-bis ([7′-(4″-N,N-dihexylaminophenylethynyl)benzo[c][1′,2′,5′]thiadiazol-4′-yl]ethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (8), and (5,15-bis([7′-(4″-N,N-dihexylaminophenylethenyl)benzo[c][1′,2′,5′]thiadiazol-4′-yl]ethynyl)-10,20-bis[2′,6′-bis(3″,3″-dimethyl-1″-butyloxy)phenyl]porphinato)zinc(II) (9) chromophores possess red-shifted absorption and emission bands that range between 650 and 750 nm that bear distinct similarities to those of the chlorophylls and structurally related molecules. Interestingly, the measured radiative decay rate constants for these emitters track with the integrated oscillator strengths of their respective x-polarized Q-band absorptions, and thus define an unusual family of high quantum yield near infrared fluorophores in which emission intensity is governed by a simple Strickler–Berg dependence.

Herein we report the synthesis of new gold nanoparticle-bacteriochlorin conjugate (Au-NP-PS) as a highly efficient photoacoustic (PA) imaging agent. The conjugate was obtained by reacting a water soluble thio-bacteriochlorin (derived from bacteriochlorophyll-$a)$ with Au-NP. The resulting NPs were characterized by UV-vis, TEM (transmission electron microscopy)/HRTEM (high resolution TEM) and diffraction pattern. The results obtained from in vitro studies suggest that due to conjugation between the PS and Au-NPs, the photoacoustic (PA) signals from the Au-NP-PS were greatly enhanced by a factor of 2.4 compared to that from PS alone.

Er${}^{3+}$/Yb${}^{3+}$ co-doped Y₂O₃ transparent ceramics were fabricated by vacuum sintering method. The Y₂O₃: Er${}^{3+}$:Yb${}^{3+}$ nonopowders were prepared by co-precipitation method in advance. The morphology of powders and ceramics as investigated. The powders exhibited well dispersive condition with 100nm in diameter. The compactness of ceramics increased obviously with the increasing temperature. No pore was found in the ceramic sintered at $1800^{\circ }$C. The ceramic samples showed intense near infrared luminescence peaking at 1535nm under the excitation of 980nm lasers, assigned to the ${}^4{I}_{13∕2}{\to }^4{I}_{15∕2}$ transition of Er${}^{3+}$. The intense up-conversion emissions were observed under the excitation of 980nm and 1550nm lasers.

Blood glucose monitoring systems (BGMSs) play a crucial role in health care applications. Invasive measurements are more accurate while non-invasive BGMS encourage self monitoring and reduce the cost of health care. Though multiple sensor data acquisition and suitable processing improve accuracy, self-monitoring becomes difficult in such non-invasive systems due to multiple signal acquisition. This paper investigates a non-invasive BGMS prototype that renders accurate measurements by statistically processing a single sensor data. The developed prototype is based on near-infrared (NIR) spectroscopy, which provides an electronic voltage that gets mapped to corresponding blood glucose level. This mapping is proposed using two different statistical regression approaches, parametric Bayesian Regression (BR) approach and the non-parametric Gaussian Process Regression (GPR) approach. Dataset is acquired from 33 subjects who visited Ramaiah Medical College Hospital, India. On each subject, voltage from the BGMS prototype and corresponding invasively obtained blood glucose level have been recorded. The BR and GPR approaches are trained with 75% of the data while the remaining 25% is used for testing. Test results show that BR approach renders root mean square error (RMSE) of 3.7mg/dL, while the mean absolute percentage error (MAPE) is around 2.5. The GPR with different radial basis function kernels revealed that a multiquadric kernel provides a lowest RMSE of 3.28mg/dL and lowest MAPE of 2.2, thus outperforming the parametric BR approach. Investigations also show that for a training data of less than 15 entries, BR renders better accuracy than the GPR approach.