Chromotropic acid-activated silver nanoparticles: a convenient colorimetric sensor for selective determination of divalent and trivalent iron ions. - Nguyen-Huynh, Nam-Phuong; Phan, Hong-Phuong; Lam, Hoa-Hung; Do, Thi-An-Sa; Nguyen, Phuc-Thanh-Duy; Tran, Thi-Kieu-Anh; Reina, Antonio; Dang-Bao, Trung (Chemical Papers, 2025)