M. Santonico

Design and test of a biosensor-based multisensorial system: a proof of concept study.

Sensors are often organized in multidimensional systems or networks for particular applications. This is facilitated by the large improvements in the miniaturization process, power consumption reduction and data analysis techniques nowadays possible. Such sensors are frequently organized in multidimensional arrays oriented to the realization of artificial sensorial systems mimicking the mechanisms of human senses. Instruments that make use of these sensors are frequently employed in the fields of medicine and food science. Among them, the so-called electronic nose and tongue are becoming more and more popular. In this paper an innovative multisensorial system based on sensing materials of biological origin is illustrated. Anthocyanins are exploited here as chemical interactive materials for both quartz microbalance (QMB) transducers used as gas sensors and for electrodes used as liquid electrochemical sensors. The optical properties of anthocyanins are well established and widely used, but they have never been exploited as sensing materials for both gas and liquid sensors in non-optical applications. By using the same set of selected anthocyanins an integrated system has been realized, which includes a gas sensor array based on QMB and a sensor array for liquids made up of suitable Ion Sensitive Electrodes (ISEs). The arrays are also monitored from an optical point of view. This embedded system, is intended to mimic the working principles of the nose, tongue and eyes. We call this setup BIONOTE (for BIOsensor-based multisensorial system for mimicking NOse, Tongue and Eyes). The complete design, fabrication and calibration processes of the BIONOTE system are described herein, and a number of preliminary results are discussed. These results are relative to: (a) the characterization of the optical properties of the tested materials; (b) the performance of the whole system as gas sensor array with respect to ethanol, hexane and isopropyl alcohol detection (concentration range 0.1–7 ppm) and as a liquid sensor array (concentration range 73–98 μM).

Prostate cancer diagnosis through electronic nose in the urine headspace setting: a pilot study.

Background:To evaluate the efficacy of prostate cancer (PCa) detection by the electronic nose (EN) on human urine samples.Methods:Urine samples were obtained from candidates of prostate biopsy (PB). Exclusion criteria were a history of urothelial carcinoma or other malignant disease, urine infection, fasting for <12u2009h before PB or ingestion of alcohol or foods that might alter the urine smell in the last 24u2009h. The initial part of the voided urine and the midstream were collected separately in two sterile containers. Both samples were analyzed by the EN immediately after the collection. All patients underwent a standard transperineal, transrectal-ultrasound-guided PB. The pathological results were compared with the outcomes of the EN. Sensitivity and specificity of EN were assessed.Results:Forty-one men were included in the study. Fourteen out of the 41 patients were positive for PCa. Midstream urine did not correlate significantly neither with a positive nor with a negative PB. Instead, significantly different results on the initial part of the urine stream between positive and negative PBs were obtained. The EN correctly recognized 10 out of the 14 cases (that is, sensitivity 71.4% (confidence interval (CI) 42–92%)) of PCa while four were false negatives. Moreover, the device recognized as negative 25 out of the 27 (that is, specificity 92.6% (CI 76–99%)) samples of negative PBs, with only two false positives.Conclusions:We believe this is the first demonstration of an olfactory imprinting of the initial part of the urine stream in patients with PCa that was revealed by an EN, with high specificity.

BIONOTE e-nose technology may reduce false positives in lung cancer screening programmes

OBJECTIVESnBreath composition may be suggestive of different conditions. E-nose technology has been used to profile volatile organic compounds (VOCs) pattern in the breath of patients compared with that of healthy individuals. BIOsensor-based multisensorial system for mimicking NOse, Tongue and Eyes (BIONOTE) technology differs from Cyranose® based on a set of separate transduction features. On the basis of our previously published experience, we investigated the discriminating ability of BIONOTE in a high-risk population enrolled in a lung cancer screening programme.nnnMETHODSnOne hundred individuals were selected for BIONOTE based on the attribution to the high-risk category (i.e. age, smoking status, chronic obstructive pulmonary disease status) of the University Campus Bio-Medico lung screening programme. We used a measure chain consisting of (i) a device named Pneumopipe (EU patent: EP2641537 (A1):2013-09-25) able to catch exhaled breath by an individual normally breathing into it and collect the exhalate onto an adsorbing cartridge; (ii) an apparatus for thermal desorption of the cartridge into the sensors chamber and (iii) a gas sensor array which is part of a sensorial platform named BIONOTE for the VOCs mixture analysis. Partial least square (PLS) has been used to build up the model, with Leave-One-Out cross-validation criterion. Each breath fingerprint analysis costs €10.nnnRESULTSnThe overall sensitivity and specificity were 86 and 95%, respectively, delineating a substantial difference between patients and healthy individuals.nnnCONCLUSIONSnOur preliminary data show that BIONOTE technology may be used to reduce false-positive rates resulting from lung cancer screening with low-dose computed tomography in a cost-effective fashion. The model will be tested on a larger number of patients to confirm the reliability of these results.

Unmasking of Olive Oil Adulteration Via a Multi-Sensor Platform

Methods for the chemical and sensorial evaluation of olive oil are frequently changed and tuned to oppose the increasingly sophisticated frauds. Although a plethora of promising alternatives has been developed, chromatographic techniques remain the more reliable yet, even at the expense of their related execution time and costs. In perspective of a continuous increment in the number of the analyses as a result of the global market, more rapid and effective methods to guarantee the safety of the olive oil trade are required. In this study, a novel artificial sensorial system, based on gas and liquid analysis, has been employed to deal with olive oil genuineness and authenticity issues. Despite these sensors having been widely used in the field of food science, the innovative electronic interface of the device is able to provide a higher reproducibility and sensitivity of the analysis. The multi-parametric platform demonstrated the capability to evaluate the organoleptic properties of extra-virgin olive oils as well as to highlight the presence of adulterants at blending concentrations usually not detectable through other methods.

A smart pill for drug delivery with sensing capabilities.

In this paper a novel system for local drug delivery is described. The actuation principle of the micropump used for drug delivery relies on the electrolysis of a water-based solution, which is separated from a drug reservoir by an elastic membrane. The electrolytically produced gases pressurize the electrolytic solution reservoir, causing the deflection of the elastic membrane. Such deflection, in turn, forces the drug out of its reservoir through a nozzle. The proposed system is integrated in a swallowable capsule, equipped with an impedance sensor useful to acquire information on the physiological conditions of the tissue. Such information can be used to control pump activation.

A sensorial platform for mozzarella cheese characterization and authentication

Mozzarella cheese is one of the most counterfeited dairy product worldwide, with implications concerning either economical and health issues. In the context of food quality monitoring and authentication, a non-destructive multi-sensorial analytic approach is proposed. A minimally invasive evaluation of the mechanical properties of the mozzarella cheese as well as of its preserving whey has been performed by means of a mechanical and a liquid sensor, respectively. Data fusion of both approaches allowed a good and easy discrimination between mozzarella cheese samples having different brand provenance and milk composition.

An investigation on e-nose platform relevance to respiratory diseases

The e-nose platform here presented gather up 190 sensors belonging to four different e-nose technologies. This platform is used in the context of a European project (U-Biopred) measuring exhaled breath samples collected from patients affected by mild or severe asthma. Sensor responses are investigated asking which disease can be diagnosed on the basis of sensor correlation with specific clinical parameters.

The Presence of the Fibonacci Numbers in Passive Ladder Networks: The Case of Forbidden Bands [Historical Corner]

This paper takes into consideration a number of different ladder networks showing links with the so-called Golden Ratio φ = 1.6180339..., which is embedded into the Fibonacci sequence. Discreteness and periodicity in electronic ladder networks seem to appear as the main features able to include Fibonacci numbers. For instance, in the telecommunication environment, transmission lines can be studied with a given approximation by simplified discrete ladder networks made by a sequence of passive identical cells, such as R-R; R-C; R-L; C-R; L-R; L-C; C-L; directly and electrically coupled each other. In this context, the so called Golden Ratio frequently appears in particular conditions, without a specific reason, at least to our best knowledge, and its presence, so far, still does represent a sort of mystery.

Analysis of volatile organic compounds: an innovative approach to heart failure characterization in older patients

BACKGROUNDnAnalysis of exhaled volatile organic compounds (VOCs) may be applied for diagnostic purposes in some chronic diseases, but there are no data on their role for discriminating people with congestive heart failure (CHF), particularly in older patients where natriuretic peptides have lower accuracy. We evaluated whether VOCs analysis can discriminate patients with or without CHF, stratify CHF severity and predict the response to therapy of decompensated CHF.nnnMETHODS AND RESULTSnWe recruited 89 subjects admitted to an acute care ward with acutely decompensated CHF, 117 healthy controls and 103 chronic obstructive pulmonary disease (COPD) controls. CHF patients performed echocardiography. VOCs were collected using the Pneumopipe® and analyzed with the BIONOTE electronic nose. Partial least square analysis was used to evaluate the discriminative capacity of VOCs. Accuracy in discrimination of CHF versus healthy and COPD controls was 81% and 69%, respectively; accuracy did not decrease in a sensitivity analysis excluding subjects younger than 65 and older than 80 years. In CHF patients VOCs pattern could predict with fair precision ejection fraction and systolic pulmonary arterial pressure, but not changes in weight due to therapy.nnnCONCLUSIONSnVOCs pattern is able to discriminate older CHF patients from healthy people and COPD patients and correlates with cardiac function markers.

Advances in the electronics for cyclic voltammetry: the case of gas detection by using microfabricated electrodes.

This paper presents an advanced voltammetric system to be used as electronic tongue for liquid and gas analysis. It has been designed to be more flexible and accurate with respect to other existing and similar systems. It features improved electronics and additional operative conditions. Among others these include the possibility to optically excite the solution and to treat the output signal by a differentiation process in order to better evidence the existence of small details in the response curve. Finally by the same type of tongue preliminary results are shown dealing with O2 and CO2 concentration measurements in appropriate solutions.