Last Advances in Silicon-Based Optical Biosensors Fernández Gavela, Adrián; Grajales García, Daniel; Ramirez, Jhonattan C ...
Sensors,
02/2016, Letnik:
16, Številka:
3
Journal Article, Book Review
Recenzirano
Odprti dostop
We review the most important achievements published in the last five years in the field of silicon-based optical biosensors. We focus specially on label-free optical biosensors and their ...implementation into lab-on-a-chip platforms, with an emphasis on developments demonstrating the capability of the devices for real bioanalytical applications. We report on novel transducers and materials, improvements of existing transducers, new and improved biofunctionalization procedures as well as the prospects for near future commercialization of these technologies.
•AuNPs as colorimetric and fluorimetric chemosensors.•Sensing metal ions with Au and Ag nanoparticles.•AgNPS as colorimetric and fluorimetric chemosensors.•Biomedical and environmental applications.
...In the last decade, metallic nanoparticles of noble metal ions as gold and silver have received much attention mainly due to their colorimetric properties. These metallic functionalised nanoparticles offered an enormous possibility of applications in many scientific and technical fields. As hybrid materials combining large surfaces with important optic and electronic properties demonstrate to be highly sensitive to the presence of metal ions in their surroundings. Special attention has being paid to the applications of gold, silver and alloys nanoparticles as fluorescent and/or colorimetric systems for detection of metals, mainly in the presence of heavy and toxic metal ions. In the present review we have focused on the advances and novelties reported in the field during the last 5 years.
Purpose
To elucidate the potential role of eleven single nucleotide polymorphisms (SNPs) in the most relevant lipid metabolism genes in Northern Spanish patients with age‐related macular degeneration ...(AMD).
Methods
A case‐control study of 228 unrelated native Northern Spanish patients diagnosed with AMD (73 dry and 155 wet) and 95 healthy controls was performed. DNA was isolated from peripheral blood and genotyped for the SNPs APOE rs429358 and rs7412; CTEP rs3764261; LIPC rs10468017 and rs493258; LPL rs12678919; ABCA1 rs1883025; ABCA4 rs76157638, rs3112831 and rs1800555; and SCARB1 rs5888, using TaqMan probes. An additional association study of ε2, ε3 and ε4 major isoforms of APOE gene with AMD has been carried out.
Results
The allele and genotype frequencies for each of the eleven sequence variants in the lipid metabolism genes did not show significant differences when comparing AMD cases and controls. Statistical analysis revealed that APOE‐ε2 carrier genotypes were less frequently observed in patients with wet AMD compared to controls (5.8% versus 13.7%, respectively: p = 3.28 × 10−2; OR = 0.42, 95% CI: 0.19–0.95). The frequency of the allele T of rs10468017 (LIPC gene) was lower in dry AMD cases compared to controls (15.8 versus 27.9%, respectively: p = 8.4 × 10−3 OR = 0.57, 95% CI: 0.33–0.98).
Conclusions
Our results suggest a protective role for APOE‐ε2 allele to wet AMD in the Northern Spanish population.
Lemon is the most sensitive citrus fruit to cold. Therefore, it is of capital importance to detect and avoid temperatures that could damage the fruit both when it is still in the tree and in its ...subsequent commercialization. In order to rapidly identify frost damage in this fruit, a system based on the electrochemical impedance spectroscopy technique (EIS) was used. This system consists of a signal generator device associated with a personal computer (PC) to control the system and a double-needle stainless steel electrode. Tests with a set of fruits both natural and subsequently frozen-thawed allowed us to differentiate the behavior of the impedance value depending on whether the sample had been previously frozen or not by means of a single principal components analysis (PCA) and a partial least squares discriminant analysis (PLS-DA). Artificial neural networks (ANNs) were used to generate a prediction model able to identify the damaged fruits just 24 hours after the cold phenomenon occurred, with sufficient robustness and reliability (CCR = 100%).
Infrared (IR) spectroscopy is a vibrational spectroscopic technique useful in chemical, pharmaceutical, and forensic sciences. It is essential to identify chemicals for reasons spanning from ...scientific research and academic practices to quality control in companies. However, in some university degrees, graduate students do not get the proficiency to optimize the experimental parameters to obtain the best IR spectra; to correlate the IR spectral bands with the molecular vibrations (chemical elucidation); to have some criteria for any substance identification (especially relevant in quality control to recognize counterfeit); and to apply chemometrics for comparing, visualizing, and classifying the IR spectra. This work presents an experimental laboratory practice for an introductory teaching of the IR instrumental conditions in the identification of substances based on visual spectra comparison and statistical analysis and matching. Then, the selected IR conditions are applied to different commercial drugs, in the solid state or in solution, mostly composed of acetaminophen. Finally, the students apply chemometrics analysis to the IR data. This practice was designed for the training in a chemistry subject for undergraduate students of the chemistry, pharmacy, or forensics degrees, among others related to science, medical, food, or technological sciences.
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