Raffaele Velotta

Glucose Sensing by Time-Resolved Fluorescence of Sol-Gel Immobilized Glucose Oxidase

A monolithic silica gel matrix with entrapped glucose oxidase (GOD) was constructed as a bioactive element in an optical biosensor for glucose determination. Intrinsic fluorescence of free and immobilised GOD was investigated in the visible range in presence of different glucose concentrations by time-resolved spectroscopy with time-correlated single-photon counting detector. A three-exponential model was used for analysing the fluorescence transients. Fractional intensities and mean lifetime were shown to be sensitive to the enzymatic reaction and were used for obtaining calibration curve for glucose concentration determination. The sensing system proposed achieved high resolution (up to 0.17 mM) glucose determination with a detection range from 0.4 mM to 5 mM.

Very high sensitivity laser gyroscopes for general relativity tests in a ground laboratory

Two ring laser gyroscopes are being developed by the INFN in view of fundamental Physics applications. The scope of this activity is to `fill the gap between the present state of the art technology and the requirements in sensitivity and accuracy needed for general relativity tests. The first prototype, called GP2 and located at INFN Pisa, is dedicated to the interferometric control of the ring laser cavity form factor. The second prototype, called GINGERino, is a larger ring laser located deep underground (INFN LNGS) and has the scope of characterizing the low frequency rotational noise of the site. We show the most recent results of the two experiments.

GINGER - Toward an experimental test of General Relativity

GINGER (Gyroscopes IN General Relativity) is a proposal for measuring nthe Lense-Thirring effect using an array of ring laser-gyroscopes. Those are, nnowadays, the most sensitive inertial sensors to measure the rotation rate nof the Earth. nThe Lense-Thirring contribution to the Earth gravitational field marks itself as a tiny nDC perturbation onto

Colorimetric Immunosensor by Aggregation of Photochemically Functionalized Gold Nanoparticles

Omega

High-order Harmonics in Fragile Molecules

, the Earth rotation rate. Its magnitude is 10

Polarization, ionization and spatial gates in single attosecond pulse generation

^{-9} times Omega

The GINGER Project

nso that to be able to discriminate it a very high sensitivity and nlong measurement times in order to move toward low frequency are required. nFor such an experiment, an underground nlocation guarantees further isolation from anthropic as well as environmental ndisturbances. nGINGERINO is a single axis ring laser located inside the the nINFN Gran Sasso laboratory. It has demonstrated that the very high thermal nstability of the cave allows continuous operation, and sensitivity well below nfractions of nrad/s are feasible with duty cycle above

地下実験室における一般相対論試験のための超高感度レーザジャイロスコープ【Powered by NICT】

90%

LASERS, OPTICS, AND OPTOELECTRONICS 241101 Single-pixel coherent diffraction imaging (3 pages)

even without stabilisation of the scale factor of the ring laser. nHere we show the GINGER experiment concept together with the first evaluation of the nGINGERINO sensitiviy that shows how such a device can be of use also in earth science and related phenomena.

Interplay between Gdd-Induced Polarization Gating and Ionization for Isolated Attosecond Pulse Generation from Multi-Cycle Driving Pulses

A colorimetric immunosensor based on local surface plasmon resonance by gold nanoparticles is presented, and its application for the detection of human immunoglobulin G (IgG) is demonstrated. The color change of the colloidal solution is produced by nanoparticle aggregation, a process that can be tuned by the presence of the analyte once the nanoparticles are functionalized. In comparison to common functionalization techniques, the procedure described here is simpler, low-cost, and effective in binding antibodies upright on the gold surface. The dose–response curve is similar to that resulting in typical immunoassay platforms and is satisfactorily described by the proposed theoretical model. Human IgG at concentration levels of few hundreds of nanograms per milliliter can be detected by eyes within a few minutes, thereby making the colorimetric immunosensor proposed here a powerful tool in several areas, with urine test in medical diagnostics being the most immediate.