1,721,015 research outputs found
Chemoresistive gas sensors for colorectal adenomas screening through faecal analysis
No full textDue to the change in the metabolic activity of the intestine when affected by a colorectal adenoma/carcinoma and to the production of colorectal cancer (CRC) biomarkers, the odor of feces is altered in comparison with healthy samples. Our research team has developed a portable device for the preliminary and non-invasive screening of CRC at all stages, named SCENT A1 (realized by SCENT S.r.l.)
Sensori per gas applicati alla diagnostica tumorale
No full textIl team del Laboratorio Sensori (LS) del Dipartimento di Fisica e Scienze della Terra dell'Università di Ferrara si occupa da oltre un ventennio dello studio e della realizzazione di sensori per gas. Tali dispositivi sono basati su materiali semiconduttori sotto forma di piccoli grani di dimensioni nanometriche, capaci di variare la propria resistenza elettrica quando entrano in contatto con i gas. nel corso degli ultimi cinque anni, la ricerca del LS si è concentrata proprio sulla applicazione dei sensori per gas alla medicina preventiva. Grazie alla start-up SCENT S.r.l. sono stati realizzati due dispositivi, uno per la diagnosi preventiva del tumore al colon retto mediante l'odore delle feci, il secondo per il monitoraggio tumorale mediante le esalazioni prodotte da campioni di sangue
Detection of tumor markers on feces with nanostructured sensors
No full textDeath for tumors is a worldwide health problem, with colorectal cancer (CRC) in particular showing to be one of the malignant tumors with the highest incidence for both genders, and with high mortality rate if not treated in time. To gain advantage on the neoplasia, and being able to identify and remove CRC in his benignant stage, pre-screening protocols like fecal occult blood test (FOBT) have been developed, and high interest from the scientific community have been shown on electronic noses, able to detect particular tumor markers secreted from cancer cells, different from blood (which may not show up at all in some cases). The goal of this book is to show the results obtained, thanks to an ongoing and recognized research from the Laboratory of Sensors of the University of Ferrara, with a different kind of technological approach, starting from the laboratory setup gases tests to the patented threshold system, based on nanostructured chemoresistive sensors, to detect the presence of both benignant polyps and CCR from the samples of feces obtained from people willingly to monitor themselves with this brand new pre-screening test
Overview of Gas Sensors Focusing on Chemoresistive Ones for Cancer Detection
No full textThe necessity of detecting and recognizing gases is crucial in many research and application
fields, boosting, in the last years, their continuously evolving technology. The basic detection
principle of gas sensors relies on the conversion of gas concentration changes into a readable signal
that can be analyzed to calibrate sensors to detect specific gases or mixtures. The large variety of gas
sensor types is here examined in detail, along with an accurate description of their fundamental characteristics
and functioning principles, classified based on their working mechanisms (electrochemical,
resonant, optical, chemoresistive, capacitive, and catalytic). This review is particularly focused on
chemoresistive sensors, whose electrical resistance changes because of chemical reactions between
the gas and the sensor surface, and, in particular, we focus on the ones developed by us and their
applications in the medical field as an example of the technological transfer of this technology to
medicine. Nowadays, chemoresistive sensors are, in fact, strong candidates for the implementation
of devices for the screening and monitoring of tumors (the second worldwide cause of death, with
~9 million deaths) and other pathologies, with promising future perspectives that are briefly discussed
as well
Chemoresistive Nanosensors Employed to Detect Blood Tumor Markers in Patients Affected by Colorectal Cancer in a One-Year Follow Up
No full textColorectal cancer (CRC) represents 10% of the annual tumor diagnosis and deaths occurring worldwide. Given the lack of specific symptoms, which could determine a late diagnosis, the research for specific CRC biomarkers and for innovative low-invasive methods to detect them is crucial. Therefore, on the basis of previously published results, some volatile organic compounds (VOCs), detectable through gas sensors, resulted in particularly promising CRC biomarkers, making these sensors suitable candidates to be employed in CRC screening devices. A new device was employed here to analyze the exhalations of blood samples collected from CRC-affected patients at different stages of their pre- and post-surgery therapeutic path, in order to assess the sensor’s capability for discriminating among these samples. The stages considered were: the same day of the surgical treatment (T1); before the hospital discharge (T2); after one month and after 10–12 months from surgery (T3 and T4, respectively). This device, equipped with four different sensors based on different metal–oxide mixtures, enabled a distinction between T1 and T4 with a sensitivity and specificity of 93% and 82%, respectively, making it suitable for clinical follow-up protocols, patient health status monitoring and to detect possible post-treatment relapses
MOX Nanosensors to Detect Colorectal Cancer Relapses from Patient’s Blood at Three Years Follow-Up, and Gender Correlation
No full textColorectal cancer represents 10% of all the annual tumors diagnosed worldwide, being often not timely diagnosed, because its symptoms are typically lacking or very mild. Therefore, it is crucial to develop and validate innovative low-invasive techniques to detect it before becoming intractable. To this aim, a device equipped with nanostructured gas sensors has been employed to detect the airborne molecules of blood samples collected from healthy subjects, and from colorectal cancer affected patients at different stages of their pre- and post-surgery therapeutic path. Data was scrutinized by using statistical standard techniques to highlight their statistical differences, and through principal component analysis and support vector machine to classify them. The device was able to readily distinguish between the pre-surgery blood samples (i.e., taken when the patient had cancer), and the ones up to three years post-surgery (i.e., following the tumor removal) or the ones from healthy subjects. Finally, the correlation of the sensor responses with the patient/healthy subject’s gender was investigated, resulting negligible. These results pave the path toward a clinical validation of this device to monitor the patient’s health status by detecting possible relapses, to parallel to clinical follow-up protocols
Reproducibility and Repeatability Tests on (SnTiNb)O2 Sensors in Detecting ppm-Concentrations of CO and Up to 40% of Humidity: A Statistical Approach
No full textNowadays, most medical-diagnostic, environmental monitoring, etc. devices employ sensors whose fabrication reproducibility and response repeatability assessment are crucial. The former consists of large-scale sensor manufacture through a standardized process with almost identical morphology and behavior, while the latter consists of giving the same response upon repeating the same stimulus. The thermo-activated chemoresistive sensors, which change their conductance by interacting with the molecules composing the surrounding gas, are currently employed in many devices: in particular, thick-film (SnTiNb)O2 nanosensors were demonstrated to be particularly suitable in the medical and biological fields. Therefore, a set of thirteen of them, randomly selected from the same screen-printing deposition, were laboratory tested, and the outcomes were statistically analyzed in order to assess their consistency. At first, the working temperature that maximized both the sensor sensitivity and response repeatability was identified. Then, the sensors were subjected to different gas concentrations and humidities at this optimal working temperature. It resulted in the (SnTiNb)O2 nanosensors detecting and discriminating CO concentrations as low as 1 ppm and at high humidity degrees (up to 40%) with high repeatability since the response relative standard error ranged from 0.8 to 3.3% for CO and from 3.6 to 5.4% for water vapor
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