Utilisation of microbiosensors for monitoring phenols in whisky fermentation process

Biosensors for the specific, sensitive and rapid detection of analytes could play an important role in fermentation industries such as the whisky industry. Long-standing challenges remain unmet and these are associated with the establishment of low-cost, easy-to-use, miniaturised, robust, reliable and highly specific biosensors. In this paper, an optical method, and more specifically fluorescence, is used for the development of a portable biosensor in combination with enzyme technology and microfabrication for the determination of phenols in smoked whisky. At present, chromatographic techniques are utilised by taking a single sample from the fermentation vessel, which may not be totally representative, so an in situ biosensor can improve the quality control during the fermentation process. The enzyme tyrosinase and a fluorescence ruthenium complex oxygen indicator were used for the detection of different phenol percentage. The enzyme and the indicator were immobilised in polymeric films during the microfabrication process. Furthermore, a comparative assessment of the enzyme and the aptamer technologies are discussed. During the last 20 years since the SELEX method developed, over 2000 papers related to aptamers or SELEX have been published and the aptamer biosensors have been enchanced and many new DNA aptamers have been developed. The utilisation of aptamer technology is discussed and advantages over the enzyme biosensor are highlighted for future work

A Practical application of energy harvesting based on piezoelectric technology for charging portable electronic devices

Developing methods for energy harvesting from the human body is a research field that can offer remarkable advances in medical and portable electronic devices, such as glucose monitoring (CGM) systems and cardiac pacemakers. Proper functionality of these devices relies heavily on the continuous supply of a sufficient amount of electricity and piezoelectricity must be included in the search of methods that can improve the aforementioned portable medical devices. This paper focuses on energy harvesting systems which the use of smart materials, such as piezoelectric transducers, in order to produce and save energy, exploiting the body as an energy source. This work also presents the implementation of two applications which are based on piezoelectricity in order to produce and save energy in a tiny battery. The first application involves the construction of a piezoelectric glove which produces energy from the force exerted by the fingers, using as base materials piezoelectric transducers. The practical implementation of this application and the measurements made on an integrated circuit, proved that 0.3236W of energy can be produced, by exerting force by the fingers on a flat surface. Moreover, a keystroke scenario and a scenario of using a tablet were investigated in which, 0.0187W were produced in 25 minutes and 0.0267W in 9 minutes, respectively. The second application involves the implementation of a piezoelectric wireless computer mouse which produces electricity, utilising the force exerted by the fingers clicking on mouse buttons. The assessment of this application proved that the battery voltage increased from 0.61V to 0.7V with 375 mouse clicks

Fluorescence based low-cost microbiosensors using simultaneously microfabrication process and enzyme immobilisation

A novel one-step microfabrication process of SU-8 films is proposed for developing inexpensive, small size and light-weight optical glucose micro-biosensors. Experimental work was performed in order to investigate whether the widely used in MEMS applications SU-8 photoresists polymers, can be utilised as immobilisation matrices for the simultaneous encapsulation of an oxygen-sensitive fluorescent indicator and glucose oxidase. The enzyme immobilisation, the encapsulation of the indicator and the patterning of the SU-8 take place simultaneously, thus offering a significant simplification of the microfabrication process. Despite the process involved contact with organic solvents, UV-light exposure and heating for pre- and post-bake, and the embedding of the enzyme in a hard and rigid epoxy resin matrix, it was observed that the enzyme demonstrated activity after encapsulation in SU-8. Testing of the immobilised enzyme´s activity inside the SU-8 matrix, was carried out with the measurement of oxygen consumption using an oxygen-sensitive indicator during the enzymatic oxidation of glucose. Negligible variation in fluorescence intensity upon the addition of glucose was observed in films without enzyme, whereas films with encapsulated enzyme and oxygen-sensitive fluorescent indicator showed a very clear increase in fluorescence intensity upon addition of glucose. A high transparency and negligible fluorescence of the SU-8 films were observed. The presented work opens up new possibilities for combining BioMEMS, advanced optoelectronic components with smart biosensor technology for personalised medicine diagnostic applications

Prevalent somatic BRCA1 mutations shape clinically relevant genomic patterns of nasopharyngeal carcinoma in Southeast Europe

Genomic patterns of nasopharyngeal carcinomas (NPCs) have as yet been studied in Southeast Asian (SEA) patients. Here, we investigated genomic patterns of locally advanced NPC Southeast European (SEE) patients treated with chemoradiotherapy. We examined 126 tumors (89% EBV positive) from Greek and Romanian NPC patients with massively parallel sequencing. Paired tumor-cell-rich (TC) and infiltrating-lymphocyte-rich (TILs) samples were available in 19 and paired tumor-germline samples in 68 cases. Top mutated genes were BRCA1 (54% of all tumors); BRCA2 (29%); TP53 (22%); KRAS (18%). Based on the presence and number of mutations and mutated genes, NPC were classified as stable (no mutations, n = 27); unstable (>7 genes with multiple mutations, all BRCA1 positive, n = 21); and of intermediate stability (1–7 singly mutated genes, n = 78). BRCA1 p.Q563* was present in 59 tumors (48%), more frequently from Romanian patients (p < 0.001). No pathogenic germline mutations were identified. NPC exhibited APOBEC3A/B and nucleotide-excision-repair-related mutational signatures. As compared to TC, TILs demonstrated few shared and a higher number of low frequency private mutations (p < 0.001). In multivariate analysis models for progression-free survival, EBV positivity was a favorable prognosticator in stable tumors; BRCA1 mutations were unfavorable only in tumors of intermediate stability. In conclusion, other than described for SEA NPC, somatic BRCA1 mutations were common in SEE NPC; these were shared between TC and TILs, and appeared to affect patient outcome according to tumor genomic stability status. Along with the identified mutational signatures, these novel data may be helpful for designing new treatments for locally advanced NPC. © 2017 UIC