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An anoporous anodica lumina( NAA)-based sensors ystem for the detection of Mycoplasma was developed through the implementation of "molecular gates" selectivet ot he presence of this bacterium. The capped support showed an egligible cargo release, while presence of Mycoplasma genomic DNA resulted in the release of rhodamine Bf luorescent dye. This sensor system presentsalimit of detection of 20 genomic DNA co-pies·mL À1 and was applied to the detection of Mycoplasma bacteria in competitive environments, such as culture cell media.Mycoplasma is as mall bacterium (diameter0 .2 mm) without cell wall, immunet oc ommon antibiotic, capable of passing through bacterial filters and of great importance because of its commonp resence in cell cultures in clinical, research and biopharmaceutical industry. [1] Besides, Mycoplasma is also related with the development of important pathologies such as pneumonia,r heumatoid arthritis, cancer andn on-gonococcal urogenital diseases, among others. [2][3][4][5][6] Historically,p olymerase chain reaction( PCR) methods and culture-based approaches have been used extensively for Mycoplasma detection. However,e ven thought hese methods are very sensitive, they have several drawbacks such as high cost, the need of trained personnel, and ar elativelyl ong time before results are obtained. [7] As an alternative, the design of new sensings ystemsf or Mycoplasma detection that overcome the cited drawbacks are of importance and have been recently

This review includes examples of silica-based, chromo-fluorogenic nanosensors with the aim of illustrating the evolution of the discipline in recent decades through relevant research developed in our group. Examples have been grouped according to the sensing strategies. A clear evolution from simply functionalized materials to new protocols involving molecular gates and the use of highly selective biomolecules such as antibodies and oligonucleotides is reported. Some final examples related to the evolution of chromogenic arrays and the possible use of nanoparticles to communicate with other nanoparticles or cells are also included. A total of 64 articles have been summarized, highlighting different sensing mechanisms.

The consumption of illicit drugs has increased exponentially in recent years and has become a problem that worries both governments and international institutions. The rapid emergence of new compounds, their easy access, the low levels at which these substances are able to produce an effect, and their short time of permanence in the organism make it necessary to develop highly rapid, easy, sensitive, and selective methods for their detection. Currently, the most widely used methods for drug detection are based on techniques that require large measurement times, the use of sophisticated equipment, and qualified personnel. Chromo‐ and fluorogenic methods are an alternative to those classical procedures.

The role of oxidative stress (OS) in cancer is a matter of great interest due to the implication of reactive oxygen species (ROS) and their oxidation products in the initiation of tumorigenesis, its progression, and metastatic dissemination. Great efforts have been made to identify the mechanisms of ROS-induced carcinogenesis; however, the validation of OS byproducts as potential tumor markers (TMs) remains to be established. This interventional study included a total of 80 colorectal cancer (CRC) patients and 60 controls. By measuring reduced glutathione (GSH), its oxidized form (GSSG), and the glutathione redox state in terms of the GSSG/GSH ratio in the serum of CRC patients, we identified significant changes as compared to healthy subjects. These findings are compatible with the effectiveness of glutathione as a TM. The thiol redox state showed a significant increase towards oxidation in the CRC group and correlated significantly with both the tumor state and the clinical evolution. The sensitivity and specificity of serum glutathione levels are far above those of the classical TMs CEA and CA19.9. We conclude that the GSSG/GSH ratio is a simple assay which could be validated as a novel clinical TM for the diagnosis and monitoring of CRC.

Pneumocystis pneumonia (PcP) is a disease produced by the opportunistic infection of the fungus Pneumocystis jirovecii. As delayed or unsuitable treatments increase the risk of mortality, the development of rapid and accurate diagnostic tools for PcP are of great importance. Unfortunately, current standard methods present severe limitations and are far from adequate. In this work, a time-competitive, sensitive and selective biosensor based on DNA-gated nanomaterials for the identification of P. jirovecii is presented. The biosensor consists of a nanoporous anodic alumina (NAA) scaffold which pores are filled with a dye reporter and capped with specific DNA oligonucleotides. In the presence of P. jirovecii genomic DNA, the gated biosensor is open, and the cargo is delivered to the solution where it is monitored through fluorescence spectroscopy. The use of capping oligonucleotides able to form duplex or triplex with P. jirovecii DNA is studied. The final diagnostic tool shows a limit of detection (LOD) of 1 nM of target complementary DNA and does not require previous amplification steps. The method was applied to identify DNA from P. jirovecii in unmodified bronchoalveolar lavage, nasopharyngeal aspirates, and sputum samples in 60 min. This is a promising alternative method for the routinely diagnosis of Pneumocystis pneumonia.

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