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This work reports on design and fabrication of a compact lab-on-chip system, based on detection of electrochemiluminescence (ECL) through thin film sensors. The proposed system couples an optoelectronic platform to a disposable microfluidic chip. The optoelectronic platform includes amorphous silicon photosensors for detection of ECL, while the microfluidic chip contains the ECL electrodes and the biological solutions to be analyzed. Optoelectronic characterization of photosensors and preliminary test on the ECL electrodes by cycling voltammetry show the suitability of these devices for the achievement of low-noise and high sensitive system.

The present paper describes the development of an integrated lab-on-chip, in which viral DNA amplification with real-time on-chip detection is carried out under constant temperature of 65 °C. The lab-on-chip is composed of a disposable 10-μL polydimethylsiloxane reaction chamber which is thermally and optically coupled to a glass substrate that hosts a thin-film metallic resistive heater and thin-film amorphous silicon diodes which act as temperature and radiation sensors. A loop-mediated isothermal amplification (LAMP) technique was optimized to specifically amplify parvovirus B19 DNA and coupled with Bioluminescent Assay in Real Time (BART) technology to provide real-time detection of target DNA. The experimental results demonstrate the ability of the proposed device to discriminate among different concentrations of viral DNA with an excellent agreement with standard off-chip methods.

Lab-on-Chip are miniaturized systems able to perform biomolecular analysis in shorter time and with lower reagent consumption than a standard laboratory. Their miniaturization interferes with the multiple functions that the biochemical procedures require. In order to address this issue, our paper presents, for the first time, the integration on a single glass substrate of different thin film technologies in order to develop a multifunctional platform suitable for on-chip thermal treatments and on-chip detection of biomolecules. The proposed System on-Glass hosts thin metal films acting as heating sources; hydrogenated amorphous silicon diodes acting both as temperature sensors to monitor the temperature distribution and photosensors for the on-chip detection and a ground plane ensuring that the heater operation does not affect the photodiode currents. The sequence of the technological steps, the deposition temperatures of the thin films and the parameters of the photolithographic processes have been optimized in order to overcome all the issues of the technological integration. The device has been designed, fabricated and tested for the implementation of DNA amplification through the Polymerase Chain Reaction (PCR) with thermal cycling among three different temperatures on a single site. The glass has been connected to an electronic system that drives the heaters and controls the temperature and light sensors. It has been optically and thermally coupled with another glass hosting a microfluidic network made in polydimethylsiloxane that includes thermally actuated microvalves and a PCR process chamber. The successful DNA amplification has been verified off-chip by using a standard fluorometer.

This paper presents a thin film structure suitable for low-level radiation measurements in lab-on-chip systems that are subject to thermal treatments of the analyte and/or to large temperature variations. The device is the series connection of two amorphous silicon/amorphous silicon carbide heterojunctions designed to perform differential current measurements. The two diodes experience the same temperature, while only one is exposed to the incident radiation. Under these conditions, temperature and light are the common and differential mode signals, respectively. A proper electrical connection reads the differential current of the two diodes (ideally the photocurrent) as the output signal. The experimental characterization shows the benefits of the differential structure in minimizing the temperature effects with respect to a single diode operation. In particular, when the temperature varies from 23 to 50 °C, the proposed device shows a common mode rejection ratio up to 24 dB and reduces of a factor of three the error in detecting very low-intensity light signals.