A Review of Logic Gates and Their Applications

Abstract

This paper reviews the fundamental concepts of logic gates and their classical and emerging applications across diverse fields. Logic gates are essential computational units based on Boolean operations and have been implemented in electronic, optical, chemical, and biological systems. The review briefly introduces Boolean and switching logic, followed by a focused discussion of molecular logic gates and their applications in biosensing, ion detection, disease diagnosis, cell imaging, food-safety analysis, pharmaceutical analysis, and synthetic biology. Particular attention is given to DNA-based circuits, fluorescent and electrochemical readouts, aptamer- and DNAzyme-based systems, and CRISPR-associated logic. The review further examines major challenges, including signal leakage, crosstalk, scalability, reproducibility, matrix effects, cost, and translation into point-of-care and clinical applications. Finally, the potential integration of logic-gate systems with nanotechnology and artificial intelligence is highlighted as a promising direction for developing more sensitive, adaptable, and intelligent sensing, diagnostic, and biomedical systems.