Application of fluorescent biosensors for heavy metal ions detection

Abstract

Heavy metal ions can be successfully detected by using a diverse of the developed fluorescent biosensors. A major trend in designing current fluorescent biosensors incorporates nanomaterials, such as quantum dots. Combined techniques with aptamers allow for highly sensitive analyses of different heavy metal ions. Other novel methods of detection involve whole cells, for example, bacterial bioreporters. A common way of exhibiting fluorescence is through “signal-on” and “signal-off”, where some fluorescent biosensors may depend on only one state, others rely on both states of emission. The methods detecting mercury ions listed include mercury-specific oligonucleotide (MSO) probes and a dual emission ratiometric fluorescent probe using silicon (SiNPs) or gold nanoclusters (AuNCs). Methods mentioned for arsenic ions include two different kinds of fluorescent-based aptasensors and a fluorescent DNA quantum dot. As to lead ions, a fluorescent method that utilizes the interactions between DNA aptamer, acridine orange, and nanomaterials is designed. Another method is through quantum dots and DNAzyme synergetic catalytic amplification. For cadmium ions, a whole-cell bioreporter was developed that incorporated bacterial organisms. All recently published methods shared a commonality of exceptional sensitivity and selectivity.