Absolute partial and total ionization cross sections of carbon monoxide with electron collision from 350 eV to 8000 eV

The absolute partial and total cross sections for electron impact ionization of carbon monoxide are reported for electron energies from 350 eV to 8000 eV.The product ions(CO^(+),C^(+),O^(+),CO^(2+),C^(2+),and O^(2+))are measured by employing an ion imaging mass spectrometer and two ion-pair dissociation channels(C^(+)+O^(+)and C^(2+)+O^(+))are identified.The absolute cross sections for producing individual ions and their total,as well as for the ion-pair dissociation channels are obtained by normalizing the data of CO^(+)to that of Ar^(+)from CO-Ar mixture target with a fixed 1:1 ratio.The overall errors are evaluated by considering various kinds of uncertainties.A comprehensive comparison is made with the available data,which shows a good agreement with each other over the energy ranges that are overlapped.This work presents new cross-section data with electron energies above 1000 eV.

A 640×640 ISFET array for detecting cell metabolism

Ion sensitive field effect transistor(ISFET)devices are highly accurate,convenient,fast and low-cost in the detection of ions and biological macromolecules,such as DNA molecules,antibodies,enzymatic substrates and cellular metabolites.For high-throughput cell metabolism detection,we successfully designed a very large-scale biomedical sensing application specific integrated circuit(ASIC)with a 640×640 ISFET array.The circuit design is highly integrated by compressing the size of a pixel to 7.4×7.4μm^(2)and arranging the layout of even and odd columns in an interdigital pattern to maximize the utilization of space.The chip can operate at a speed of 2.083M pixels/s and the dynamic process of the fluid flow on the surface of the array was monitored through ion imaging.The pH sensitivity is 33±4 mV/pH and the drift rate is 0.06 mV/min after 5 h,indicating the stability and robustness of the chip.Moreover,the chip was applied to monitor pH changes in CaSki cells metabolism,with pH shifting from 8.04 to 7.40 on average.This platform has the potential for continuous and parallel monitoring of cell metabolism in single-cell culture arrays.

Preparation of highly luminescent nitrogen and sulfur co-doped carbon nanoparticles for iron(Ⅲ)ions detection and cell imaging

Highly photoluminescent nitrogen and sulfur co-doped carbon nanoparticles（CNPs） ca. 56 nm have been prepared through a green one-step hydrothermal synthesis route by using millet powder as carbon sources, in which the nitrogen and sulfur co-doping improves the photoluminescent efficiency of the CNPs. The as-prepared CNPs display excellent fluorescent properties and low biotoxicity with a relatively high quantum yield of 30.4%, which have been applied for bioimaging and highly sensitive and selective detection of iron（III） ions.

A fluorescent probe for Hg^(2+)sensing in solutions and living cells with a wide working pH range

In this paper, 2-carboxybenzaldehyde rhodamine B thiohydrazine （1） was synthesized and developed as a fluorescent probe to recognize Hg2＋ in DMF/H2O （1：9, v/v） solution with high selectivity. The probe can be applied to the quantification of rig2＋ with a linear concentration range covering from 1.0 × 10^-7 mol/L to 1.0 × 10^-5 mol/L （R2 = 0.9985） and a detection limit of 4.2 × 10^-8 mol/L. The experiment results show that the response of probe 1 to Hg2＋ is pH-independent in a wide range from 4.0 to 9.0. Moreover, the probe 1 exhibits excellent selectivity toward Hg2＋ over other common metal cations. Most importantly, the probe can be employed to monitor Hg2＋ in living cells using fluorescent imaging technique with satisfied results.