Fast Detection Of Heavy Metal Ion Based On AC Electrokinetics Effect

Heavy metal elements are difficult to be biodegraded,it can enter the human body by food chain,causing harm to human body and polluting the environment through air circulation.Among these heavy metal ions,lead ion is the "culprit" that endangers human health and children's intelligence nowadays.Therefore,high sensitivity and rapid real-time detection of heavy metal elements,especially lead ion,has extremely important research significance and application value.At present,the traditional heavy metal ion detection can not meet the needs of high sensitivity and fast real-time detection,this work presented a method based on AC electrokinetics enhanced capacitive sensing with high sensitivity,easy operation and fast detection of heavy metal ion in solution and the corresponding heavy metal ion sensor is fabricated.By adjusting the testing voltage,thirteen kinds of metal ions were detected at 100 kHz and 1V,three kinds of ions were detected at 100 kHz and 0.5V and only lead ion was detected at 100 kHz and 0.3V.At 100 kHz and 300 mV,five kinds of concentration of lead ion were detected continuously,and the greater the concentration of lead ion,the greater the response,the sensor's selective ratio to lead ion was 10000:1,and its limit of detection was 50 pM.The sensor also has similar response law to the actual lead ion sample,the recovery rate of the actual sample is over 80%,which has a good practical value potential.The long-term activity of the biosensor can be guaranteed by dry incubation of glutathione in this experiment,the response of the biosensor after 28 days of dry incubation remains 75.321% of the initial value,indicating the activity of the biosensor probe.