Abstract

Obesity establishes a chronic, low-grade inflammatory and endocrine milieu that elevates cancer risk and 
worsens outcomes across multiple organs. Early interception depends on detecting compoNsite biomarker 
signatures spanning inflammatory cytokines, adipokines, oncometabolites, extracellular vesicles, and tumor
derived nucleic acids at clinically actionable concentrations and in real-world matrices complicated by 
dyslipidemia and high protein burden. Nanoscale biosensors bring the requisite surface-to-volume ratio, 
quantum and plasmonic effects, and electron transport properties to transduce scarce targets with high 
selectivity while supporting multiplexing in small sample volumes. This review charts advances in 
electrochemical, field-effect transistor, plasmonic/optical, SERS, quantum dot, nanopore, and microfluidic 
nanotechnologies tailored to the obesity–cancer interface. It emphasizes antifouling surface chemistries that 
remain specific in lipid-rich plasma, aptamer and molecularly imprinted polymer recognition layers that rival 
antibodies, and device architectures that couple pre-concentration, sorting, and readout on a single chip. 
Integration with wearable microneedles and sweat or saliva sensors points toward longitudinal, minimally 
invasive surveillance, while machine-learning fusion of multimodal signals promises individualized risk 
stratification and treatment triage. Finally, we outline validation, calibration, and regulatory pathways to move 
nano-biosensing from elegant prototypes to robust clinical tools that detect obesity-linked cancer signals 
months to years earlier than current practice.