Browsing by Author "Mittapalli R"

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    Acoustic Multi-Detection of Gliadin Using QCM Crystals Patterned with Controlled Sectors of TEM Grid and Annealed Nanoislands on Gold Electrode
    (MDPI (Basel, Switzerland), 20/04/2020) Casari Bariani G; Zhou L; Poggesi S; Mittapalli R; Manzano M; Ionescu RE
    Celiac diseases are a group of gluten ingestion-correlated pathologies that are widespread and, in some cases, very dangerous for human health. The only effective treatment is the elimination of gluten from the diet throughout life. Nowadays, the food industries are very interested in cheap, easy-to-handle methods for detecting gluten in food, in order to provide their consumers with safe and high-quality food. Here, for the first time, the manufacture of controlled micropatterns of annealed gold nanoislands (AuNIs) on a single QCM crystal (QCM-color) and their biofunctionalization for the specific detection of traces of gliadin is reported. In addition, the modified quartz crystal with a TEM grid and 30 nm Au (Q-TEM grid crystal) is proposed as an acoustic sensitive biosensing platform for the rapid screening of the gliadin content in real food products.
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    Quartz crystal microbalance genosensing of brettanomyces bruxellensis yeast in wine using a rapid and efficient drop and collect protocol
    (MDPI (Basel, Switzerland), 2021-05-18) Poggesi S; Zhou L; Bariani GC; Mittapalli R; Manzano M; Ionescu RE; Guo P; Portalone G; Pirri F
    A miniaturized quartz crystal microbalance (QCM) genosensor is proposed for sensitive and real-time detection of short ssDNA sequences (53 bp) or DNA extracted from Brettanomyces bruxellensis (Brett) yeast cells. The presence of Brett yeast causes a depreciation of the quality of aged fine wines, producing molecules of unpleasant odors and biogenic amines that are harmful to human health. More specifically, standard quartz crystal (S-QCM) and homemade 4 nm gold transmission electron microscopy (TEM)-grid patterned quartz (multi-TEM QCM) are herein proposed for biofunctionalization steps with different ssDNA sequences. By employing a rapid and efficient drop and collect protocol, the specific detection of 1 pg/µL ssDNA Brett of a short sequence and 100 ng/µL DNA of B. bruxellensis extracted from a wine sample (VR2008) is reported.
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    Robust SERS Platforms Based on Annealed Gold Nanostructures Formed on Ultrafine Glass Substrates for Various (Bio)Applications
    (MDPI (Basel, Switzerland), 2019-06) Zhou L; Poggesi S; Casari Bariani G; Mittapalli R; Adam P-M; Manzano M; Ionescu RE
    In this study, stable gold nanoparticles (AuNPs) are fabricated for the first time on commercial ultrafine glass coverslips coated with gold thin layers (2 nm, 4 nm, 6 nm, and 8 nm) at 25 °C and annealed at high temperatures (350 °C, 450 °C, and 550 °C) on a hot plate for different periods of time. Such gold nanostructured coverslips were systematically tested via surface enhanced Raman spectroscopy (SERS) to identify their spectral performances in the presence of different concentrations of a model molecule, namely 1,2-bis-(4-pyridyl)-ethene (BPE). By using these SERS platforms, it is possible to detect BPE traces (10-12 M) in aqueous solutions in 120 s. The stability of SERS spectra over five weeks of thiol-DNA probe (2 µL) deposited on gold nano-structured coverslip is also reported.