POROUS PHOSPHOLIPID NANOSHELL PROTECTED APTAMER SENSOR FOR URINE MERCURY DETECTION

Abstract

Mercury exposure has been related to neurological diseases and poisoning. Quantification of mercury in biological fluids, such as serum or urine is an important diagnostic method for mercury exposure. We have developed an aptamer-encapsulated porous phospholipid nanoshell (PPN) sensor for sensing mercury in urine using a modified 15-mer single strand DNA.1 The probe is protected from DNAse and other biofouling species by encapsulation within the porous liposomes composed of mixed phospholipids, allowing direct application of the aptamer in biological fluids containing DNAse and other biofouling materials. The encapsulated sensor was directly tested in urine samples at physiological pH. We were able to detect below 100 ppb (500 nM) Hg2+ in urine (urine mercury threshold set by Biologischer Arbeitstoff Toleranz Wert or BAT)1 with no sample preparation other than pH adjustment. These results suggest that porous phospholipid nanoshells (PPNs) can serve as a general-purpose protection scaffold for biological sensing.