Accurate and rapid diagnostics are required for environmental monitoring, food safety, and medicine in the 21^st century. Disposable sensors provide low-cost, user-friendly options for rapid measurement from clinical diagnostics to food science. Synthetic single-stranded DNA or RNA, termed aptamers, are relatively new tools with clear advantages in terms of structural, binding specificity, chemical flexibility, and new improvements in robustness in complex, regulated matrices. This review provides a comprehensive overview of nanomaterial-integrated aptamer-based biosensors, categorizing major diagnostic methods such as colorimetric, electrochemical, fluorescence, lateral flow, and CRISPR-based detection systems. Applications in clinical diagnostics, food safety, and environmental monitoring are addressed. Target accessibility, stability in vivo, and regulatory limitations are highlighted as the major challenges through the integration of recent studies. The current work aims to help researchers with designing and using long-lasting, aptamer-based nano biosensors for practical diagnostic applications.