Integration of nanostructured materials into sensors is an effective strategy to improve the performance of sensors, in terms of selectivity, sensitivity, response time and reliability. Herein, we present the design and fabrication of various nanostructured sensors and their applications in biomedical diagnosis and environmental detection. The nanostructured sensors can be integrated with plastic microfluidics and paper-based test strips to enable point-of-care tests. Several types of sensors including surface-enhanced Raman scattering sensors, colorimetric sensors, surface plasmon resonance-enhanced fluorescent sensors and electrochemical sensors are demonstrated for biomolecule and environmental pollutant detection.