Conjugation of phages with CdS nanocrystals. An alternative in the development of a new tracer for immunoassays

TOCCO, AYLÉN DI; PORCAL, GABRIELA VALERIA; MONTI, GUSTAVO ANTONIO; WENDEL, ANA; PALACIOS, RODRIGO; FERNÁNDEZ, HÉCTOR; PIERINI, GASTÓN; ZON, MARÍA ALICIA; ROBLEDO, SEBASTIÁN NOEL; ARÉVALO, FERNANDO JAVIER

MICROCHEMICAL JOURNAL

ELSEVIER SCIENCE BV

Año: 2024 vol. 196

0026-265X

In this work we develop a new tracer based on phage particles labeled with CdS nanocrystals for the constructionof an electrochemical immunoassays. Therefore, M13 phages and CdS nanocrystals stabilized with the 3-mercap-topropionic acid were conjugated. Different routes for binding the CdS nanocrystals to the phage coat werestudied. A complete characterization of the new tracer was performed using uv–visible and fluorescence mi-croscopies, and transmission electron microscopy. The tracer was evaluated in the detection and quantification ofan herbicide in river water using an electrochemical immunoassay. As a concept proof, molinate herbicide waschosen, which is a derivative of the thiocarbamate family. Excellent analytical parameters were achieved. Theperformance of CdS nanocrystals-phage was compared to unlabeled phage, where a significant improvement insensitivity was found. Thus, CdS nanocrystals-phage are presented as an excellent alternative to the markerscommonly used in the development of immunoassays.