Nucleic acids are the fundamental building blocks of life and are found in all living things. In recent years, their functions have been shown to extend beyond the Watson-Crick base pair recognition of complementary strands. Molecules (known as aptamers) consisting of 40-50 nucleotides have been isolated that are able to bind a broad range of molecules with high affinity and specificity. The molecules recognized by aptamers range from small organic molecules to proteins, cells and even intact viral particles. Catalytic DNA molecules called NAzymes (RNAzyme or DNAzyme) have also been shown to exist and, when combined with aptamers, are known as aptazymes. These biomolecules can be used to develop smart and innovative biosensors for environmental analysis. Monitoring of contaminants in the air, water and soil is a key component in understanding and managing risks to human health and ecosystems. This, in conjunction with the time and cost involved in traditional chemical analysis, means there is a growing need for simple, rapid, cost-effective and portable screening methods. Biosensors are compact devices which complement current field screening and monitoring methods.

Biosensor techniques for environmental monitoring; Nucleic acids as biorecognition element in biosensor development; Genosensing environmental pollution; Aptamer based biosensor for environmental monitoring; Catalytic nucleic acid biosensors for environmental monitoring; Nucleic acid-based biosensors for the detection of DNA damage; Detection of damage to DNA using electrochemical and piezoelectric DNA-based biosensors; New trends in DNA sensors for environmental applications. Nanomaterials, miniaturisation and lab-on-a-chip technology; Conclusions and criticisms