This study describes the use of a smartphone for monitoring acid–base titrations on wax printed paper microzones. An array of twelve microzones of 5 mm diameter each was wax printed on filter paper. The analytical performance of the proposed devices was explored with acid–base titrations examples, where jaboticaba peel extract was used as a natural pH indicator. The color intensity was captured using a smartphone and analyzed through a free App named Photometrix^®. Before titrations, color intensity versus pH was calibrated to be used as a reference in titrations as (i) strong acid versus strong base; (ii) strong base versus strong acid; and (iii) weak acid versus strong base. In all examples, images were obtained after the addition of each aliquot of titrant solutions. The obtained titration curves showed the same behavior as the conventional titration curves. After evaluating the feasibility of the proposed methodology, the concentration level of acetic acid was obtained in three vinegar samples. Although the obtained values ranged from 5% to 8% compared to the concentrations on the conventional method, the proposed methodology presented high analytical reliability. The calculated concentrations of acetic acid in three samples ranged from 3.87% to 3.93%, and the proposed methodology did not significantly differ from classic acid–base titration at a confidence level of 95%. The acid–base titration on paper-based devices is outstanding, since any titration can be completed within 5 min using 20 µL volumes. Besides, the use of a smartphone to capture images followed by analysis in a free app offers simplicity to all users. The proposed methodology arises as a new strand to be exploited in the diffusion of the analytical chemistry education field as well as an alternative for quantitative analysis with extremely simplified instrumentation.

Cell-membrane-coated nanoparticles (NPs) have important applications in the prevention, diagnosis, and treatment of diseases. Here, we demonstrate the preparation of a multifunctional membrane camouflage system consisting of Zn-Mn ferrite and rare-earth (Nd, Yb, and Ho)-doped fluoride NPs encapsulated into the red blood cell membrane (RBCm). Energy-dispersive spectroscopy and transmission electron microscopy of the RBCm showed the encapsulation of the magnetic and fluorescent fluoride NPs. The magnetic properties of the nanocarrier showed superparamagnetic behavior as a result of the ferrite NP and diamagnetic contribution as a result of the membrane constituents. Magnetic nanoparticle hyperthermia was found to have a lower efficiency compared to photothermal therapy (PTT) under the conditions evaluated. The photothermal conversion efficiency is found to be around 13% (excitation at 808 nm). MNH and PTT properties arise from the magnetic NPs, while the luminescent properties arise from the rare-earth-doped fluoride NPs. The Nd ions in the fluoride NP are excited at 808 nm, avoiding nonspecific tissue heating. Down-conversion peaks are related to Nd/Yb emissions, whereas upconversion peaks arise from Ho states as a result of energy transfer processes. Potential multiparametric luminescence thermometry based on the emission of Yb3+/Nd3+ intensity ratio (980/1060 nm) provides encouraging results for real-time monitoring of thermal therapy in the second biological window. The thermal sensitivity ranged from 0.58 to 0.62%K−1 at the range of 45–60 °C.

Agriculture, as a basis of sustainable development, faces increasing pressure to meet rising global food demands while confronting the increasing impacts of climate change. Precision agriculture offers a data-driven approach to address these challenges by optimizing input use, improving productivity, and reducing environmental impacts. Sensor technologies play a critical role in smart and precision agriculture, offering high-resolution spatial and temporal insights into soil conditions, plant development and environmental conditions. This review highlights the current state and future potential of various sensor and imaging systems, particularly their role in monitoring soil properties, crop nutrition, plant health and detecting biotic and abiotic stressors. Special attention is given to accessible paper-based and printed electrochemical devices for on-site soil and plant analysis, as well as active handheld multispectral sensors designed for real-time canopy assessment. The integration of sensor-derived data with predictive models, IoT networks and decision-support tools enables more precise, site-specific management, improves input efficiency and supports climate-resilient agricultural practices. By examining the capabilities, limitations and future potential of these sensing platforms, this review highlights their growing importance in advancing sustainable intensification and strengthening crop production.

Lipid phase organization, governed by membrane composition, packing density, and dynamic heterogeneity, dictates molecular partitioning and diffusion across structurally diverse lipid nanocarriers.