1 Department of Chemical Engineering, McGill University, 3610 University Street, Wong Building, Room 4180, Montréal, QC, H3A 0C5, Canada. noemie.dorvalcourchesne@mcgill.ca.
2 Department of Chemistry and Biochemistry and Centre for NanoScience Research, 7141 Rue Sherbrooke Ouest, Concordia University, Montreal, QC, H4B 1R6, Canada.
3 Department of Bioengineering, McGill University, 817 Sherbrooke Street West, Macdonald Engineering Building, Room 355, Montréal, QC, H3A 0C3, Canada.

Halide perovskite nanocrystals (HPNCs) have emerged at the forefront of nanomaterials research over the past two decades. The physicochemical and optoelectronic properties of these inorganic semiconductor nanoparticles can be modulated through the introduction of various ligands. The use of biomolecules as ligands has been demonstrated to improve the stability, luminescence, conductivity and biocompatibility of HPNCs. The rapid advancement of this field relies on a strong understanding of how the structure and properties of biomolecules influences their interactions with HPNCs, as well as their potential to extend applications of HPNCs towards biological applications. This review addresses the role of several classes of biomolecules (amino acids, proteins, carbohydrates, nucleotides, etc.) that have shown promise for improving the performance of HPNCs and their potential applications. Specifically, we have reviewed the recent advances on incorporating biomolecules with HP nanomaterials on the formation, physicochemical properties, and stability of HP compounds. We have also shed light on the potential for using HPs in biological and environmental applications by compiling some recent of proof-of-concept demonstrations. Overall, this review aims to guide the field towards incorporating biomolecules into the next-generation of high-performance HPNCs for biological and environmental applications.