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We describe herein a sensor containing nanoporous anodic alumina (NAA) as sensing platform to identify SARS-COV-2 RNA using a gating mechanism. The system is based on NAA that contains a fluorescent dye (Rhodamine B; RhB) and is capped with an oligonucleotide sequence that hybridize specifically a region of SARS-CoV-2 genome. In the presence of RNA from SARS-COV-2 virus, the oligonucleotide of the surface is displaced, uncapping the pores, and producing a delivery of RhB. The detection of the virus is achieved measuring the fluorescence of the fluorophore. The nanosensor demonstrates to be highly sensitive and selective in aqueous buffers and in biological media, having a limit of detection (LOD) of 50 ± 30 copies mL-1 of SARS-CoV-2 RNA extracted from patients. Moreover, preliminary results using 18 real nasopharyngeal swab samples indicate the potential of the system to differentiate between infected and non-infected patients. Compared to the conventional RT-PCR method, in our system there is no need for sample pretreatment or RNA isolation, providing diagnostic outcomes within 60 mins while maintaining a high level of reliability.

Abstract Background Leishmaniasis, considered by the World Health Organization as one of the most important tropical diseases, is endemic in the Mediterranean Basin. The aim of this study was to evaluate epidemiological and clinical characteristics of cutaneous (CL) and mucocutaneous leishmaniasis (MCL) in La Fe University Hospital, Valencia, Spain. The particular focus was on diagnosis techniques and clinical differences according to the immunological status of the patients. Methods An eleven-year retrospective observational study of CL and MCL episodes at the hospital was performed. Epidemiological, clinical and therapeutic variables of each case, together with the microbiological and anatomopathological diagnosis, were analyzed. Results A total of 42 patients were included, 30 of them were male and 28 were immunocompetent. Most of the cases (36/42) were diagnosed in the last 5 years (2013–2017). The incidence of CL and MCL increased from 3.6/100,000 (2006–2012) to 13.58/100,000 (2013–2017). The majority of the patients (37/42) exhibited CL, in 30 cases as single lesions (30/37). Ulcerative lesions were more common in immunosuppressed patients (13/14) than in immunocompetent patients (20/28), (P = 0.2302). The length of lesion presence before diagnosis was 7.36 ± 6.72 months in immunocompetent patients and 8.79 ± 6.9 months in immunosuppressed patients (P = 0.1863). Leishmania DNA detection (92.3%) was the most sensitive diagnostic technique followed by Giemsa stain (65%) and histopathological examination (53.8%). Twelve patients (12/42) had close contact with dogs or were living near to kennels, and 10 of them did not present underlying conditions. Intralesional glucantime (21/42) and liposomal amphotericin B (7/42) were the most common treatments administered in monotherapy. All patients evolved successfully and no relapse was reported. Conclusions Some interesting clinical and epidemiological differences were found in our series between immunocompetent and immunosuppressed patients. Future studies can take these results further especially by studying patients with biological therapy. Skin biopsies combining NAAT with histological techniques are the most productive techniques for CL or MCL diagnosis.