Dados do Trabalho

Título

COLORIMETRIC SYSTEM BASED ON POLYDIACETYLENE AND TWEEN 80 VESICLES FOR SPECIFIC DETECTION OF Pseudomonas spp.

Introdução

Early identification of contaminating and infectious microorganisms is essential for implementing control
measures in industrial and healthcare settings. For example, bacteria of the Pseudomonas genus are highly relevant in the context of contamination in dairy and meat processing plants due to their production of heat-resistant enzymes. This genus also includes species such as P. aeruginosa, an opportunistic pathogen with high risk to immunocompromised patients . In this regard, the detection methods used for decision-making in these environments should be rapid, sensitive, and easy to apply, characteristics inherent tocolorimetric platforms. In this context, polydiacetylene (PDA) vesicles are cost-effective and versatile transducer platforms. They undergo a color change from blue to pink, red, yellow, or purple during their production or when exposed to the target molecule or system alterations. This color transition is quantifiable and associated with the target molecule's concentration, making them valuable for biosensors in areas such as smart packaging and
diagnostic tests.

Material e Métodos

PDA vesicles were produced using diacetylene monomers (PCDA) and pre-established lipid compositions (PCDA/Tween80; PCDA/SPH/CHO) at a concentration of 1 mM, adapted from. The produced vesicles were characterized for size, pH, surface charge (Zeta potential), and polydispersity index. Subsequently, these vesicles were associated with a sensor molecule (receptor), and the color transition was assessed through their interaction with suspensions of P. fluorescens ATCC 13525. The sensitivity of the PCDA/Tween80 systems was evaluated in relation to the presence of bacterial suspensions at concentrations ranging from 100 to 107 CFU/mL, including P. aeruginosa ATCC 25619, E. coli ATCC 11229, and Staphylococcus sp. ATCC 6538 in 96-well plates containing 150 μL of vesicles and 50 μL of cells.

Resultados e Discussão

PCDA/Tween80 vesicles (345.3 nm, PDI 0.315, ζ -30.1 mV, pH 5.71) and PCDA/SPH/CHO vesicles (239.3 nm, PDI 0.432, ζ -21.1 mV, pH 4.78) offer rapid microorganism detection. Their uniformity and selectivity, especially PCDA/Tween80, enable cost-effective quality control of dairy and meat products.

Conclusão

These findings validate the system's selectivity, specificity, and sensitivity, enabling daily quality control of dairy and meat products.