Current Nanoscience - Online First

Mycoplasma pneumoniae (MP) is a bacterial infection and the primary causative agent for pneumonia, which poses a significant health burden and strains the medical industry. Elderly individuals, people with compromised immune systems, those with lung diseases, sickle cell disease, and children are particularly vulnerable.

To replace traditional methods, it is essential to develop an accurate method for detecting pneumonia for early diagnosis and improved treatment outcomes. In this research, a highly sensitive nanomaterial-modified DNA biosensor was developed on a concentric interdigitated electrode (concentric-IDE) sensor for diagnosing pneumonia. The sensor surface was modified with diamond nanoparticles, followed by the attachment of captured DNA to the IDE through an amine linker. On these surfaces, specific target DNA was detected at concentrations as low as 1 pM [y = 4.2x - 1.58, R² = 0.9908].

Furthermore, selective DNA was identified in mixed samples containing single- and triple-mismatched DNA sequences, with current responses increasing as target DNA concentrations increased. Control experiments performed with unrelated capture and target DNA did not result in increased current, indicating the specific detection of the target DNA.

This biosensor could be widely applied in point-of-care settings for diagnosing pneumonia, particularly in rural areas.

In recent years, azo dyes have become the dominant choice in the textile industry, accounting for about 60-70% of all dyes used, which has led to growing environmental concerns.

This research focused on the photocatalytic degradation of methyl orange (MO) and methyl green (MG) dyes using a novel g-C3N4 (GCN)/polyaniline (PANI)/Ag composite under visible light.

This composite was synthesized through a straightforward preparation process and characterized by using various techniques, including UV-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and cyclic voltammetry (CV).

Characterization results confirmed the incorporation of PANI and Ag nanoparticles into the GCN matrix. This composite enhanced the visible light absorption and improved charge separation, leading to increased photocatalytic efficiency. Photocatalytic experiments were conducted under visible light irradiation with a catalyst dosage of 10 mg in a 10-ppm solution of the MO and MG dyes mixture.

The GCN/PANI/Ag composite achieved significant degradation efficiencies of 70% for MO and 69% for MG within 120 minutes. The degradation process followed first-order kinetics, with rate constants of 0.0087 min⁻¹ for MO and 0.0086 min⁻¹ for MG, respectively. Reusability tests showed that the composite retained over 60% of its initial efficiency after five cycles. These findings highlight the potential of the GCN/PANI/Ag composite as a sustainable and effective photocatalyst for visible-light-driven dye degradation, offering an eco-friendly approach to wastewater treatment.

Identifying abdominal aortic aneurysm (AAA) and its condition is crucial for providing better treatment before rupture. Since AAA is often asymptomatic, regular monitoring is necessary for elderly individuals to detect changes in the aorta.

Although imaging techniques are commonly used to diagnose AAA, they are expensive and can cause discomfort to patients. C-reactive protein (CRP) is an acute-phase protein, and its concentration is highly correlated with the size of the abdominal aortic aneurysm (AAA) diameter. It was found that patients with elevated CRP levels above 1.4 mg/mL had an AAA expansion rate of 4.8 mM, compared to 3.9 mM in those with levels below 1.4 mg/mL. In addition, CRP helps to identify AAA in asymptomatic patients. Compared to other biomarkers, CRP levels are useful in assessing the size of AAA.

Therefore, quantifying CRP levels aids in identifying and monitoring AAA size. This research focuses on developing a CRP biosensor on a zeolite-modified electrode with a silica substrate for diagnosing AAA. An anti-CRP aptamer serves as the capture molecule, while an anti-CRP antibody functions as the detection molecule. The aptamer is conjugated with gold nanoparticles and linked to the electrode via an amine-modified zeolite to enhance aptamer immobilization.

Using an aptamer-antibody sandwich assay, a detection limit of 1 pg/mL of CRP was achieved on this surface. Furthermore, CRP-spiked serum samples showed a noticeable increase in current responses, while control proteins and complementary aptamers failed to elevate the current level, indicating the selective and specific detection of CRP.

Excessive applications of agrochemicals to meet the high food demand from ever-increasing populations are becoming a major issue for both health practitioners and environmental managers. Chemicals such as ethylene bis-dithiocarbamate pesticide mancozeb (MCZ) are known to have deleterious effects on the ecosystem. AIM: This study, aimed at assessing the suitability of cerium-doped zinc oxide (Ce-ZnO) for efficient degradation of MCZ fungicide.

The photocatalysts were synthesized using the coprecipitation method with zinc nitrate hexahydrate, cerium nitrate hexahydrate, and sodium hydroxide. The synthesized nanocomposites were further characterized by Powder X-ray Diffraction (PXRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDAX). The average crystallite size of the as-synthesized particles was found to be 31.42 nm, with very sharp PXRD peaks revealing the pure crystal nature of the particles. The photocatalytic degradation activity was evaluated following a series of experiments under natural environmental conditions. The optimal conditions for the degradation of MCZ fungicide using Ce-ZnO were found to be 10 ppm initial concentration of MCZ, 20 mg dose of the Ce-ZnO photocatalyst, 180 minutes irradiation time, and 10-11 atmospheric UV index.

At the optimum conditions, the degradation efficiency was found to be about 90% after 180 minutes. The reported photocatalytic degradation of MCZ using Ce-ZnO fits a pseudo-first-order kinetic model with an R² value of 0. 9677. Similarly, the reusability of the as-synthesized photocatalyst was evaluated and found to be active for five rounds with little change in the activity.

Thus, the degradation method in the current study can be suitable for the degradation and removal of MCZ in agricultural runoff in the field.