Cancer stem cells (CSCs) are implicated in the increase of lung cancer mortality rates. They contribute to cancer recurrence and tumor growth through inhibition of drug-induced cell death,
decreasing the efficiency of generic cancer therapy as well as photodynamic therapy (PDT). PDT can be improved to successfully treat lung cancer by using nanoparticles to mediate photochemotherapeutic compound delivery and retention in tumor tissue. By combining antibodies (Abs) to the nanoparticle-drug conjugate, targeting of tumor tissue is enhanced. In this study, a nanobioconjugate (NBC) was constructed, using a photosensitizer (PS) (AlPcS4Cl), AuNPs and Abs. The NBC was characterized, using spectroscopy and the photodynamic cell death induction was determined using biochemical assays 24 h post-irradiation. Results indicated successful conjugation of the nanocomposite. Localization of the NBC was observed in integral organelles involved in cell homeostasis. Biochemical responses of lung CSCs treated with AlPcS4Cl-AuNP and AlPcS4Cl-AuNP-Ab showed significant increase cell toxicity and death, compared to free AlPcS4Cl.