Quinonoid compounds based on 5-iodo-1,4-disubstituted-, 1,4- and 1,5-disubstituted-1,2,3-triazoles were synthesized using simple methodologies and evaluated against T. cruzi, the etiological agent of Chagas disease, and cancer cell lines PC3, HCT-116, HL-60, MDA-MB-435 and SF-295. The cytotoxic potential of the lapachones was also assayed against peripheral blood mononuclear cells (PBMC). Two compounds 6 and 12 were identified as potential hits against T. cruzi. β-Lapachone-based 1,5-disubstituted-1,2,3-triazole (12) displayed an IC₅₀/24 h = 125.1 μM, similar to benznidazole, the standard drug. Compound 12 was also more active than the precursor β-lapachone against the cancer cell lines. These compounds acting as multitarget quinoidal systems could provide promising new leads for the development of trypanocidal and/or anticancer drugs.

BTDs (2,1,3-benzothiadiazoles) are fluorescent heterocycles widely used in different applications, including biomarkers, sensing optical devices, OLEDs, organic transistors, and solar cells. This review mainly focuses on the current progress in the design of compounds derived from the BTD core, aiming for their use as chromogenic and/or fluorogenic devices for detecting anionic, cationic, and neutral analytes. Reactions and synthetic strategies that show the synthetic versatility of BTDs are initially presented, to provide a better understanding regarding the assembly of optical detection systems. The photophysical mechanisms of the detection are also described. A discussion is also presented on the target analytes for which the optical detection devices based on BTD were planned. The examples discussed here will offer the sensors community perspectives for developing new optical detection devices based on BTD for different types of analytes of importance for the most diverse areas of knowledge.

Three decades after A. P. de Silva’s seminal paper introduced the concept of logic gates at the molecular level, the field of molecular logic gates (MLGs) has witnessed significant advancements. MLGs are devices designed to perform logical operations, utilizing one or more physical or chemical stimulus signals (inputs) to generate an output response. Notably, MLGs have found diverse applications, with optical detection of analytes emerging as a notable evolution of traditional chemosensors. Organic synthesis methods are pivotal in crafting molecular architectures tailored as optical devices capable of analyte detection through logical functions. This review delves into the fundamental aspects and physical–chemical properties of MLGs, with a particular emphasis on synthetic strategies driving their design.

Optical detection devices have become an analytical tool of interest in diverse fields of science. The search for methods to identify and quantify different compounds has transposed this curiosity into a necessity, since some constituents threaten the safety of life in all its forms. In this context, 30 years ago, Prof. Prasanna de Silva presented the idea of sensors as Molecular Logic Gates (MLGs): a molecule that performs a logical operation based on one or more inputs (analytes) resulting in an output (optical modification such as fluorescence or absorption). In this review, we explore the implementation of MLGs based on the interference of a second input (second analyte) in suppressing or even blocking a first input (first analyte), often resulting in INHIBIT-type gates. This approach is interesting because it is not related to attached detecting groups in the MLG but to the relation between the first and the second input. In this sense, flexible and versatile MLGs can be straightforwardly designed based on input selection. To illustrate these cases, we selected examples seeking to diversify the inputs (first analytes and interfering analytes), outputs (turn on, turn off), optical response (fluorescent/colorimetric), and applicability of these MLGs.