Ultrasensitive Detection of Nitrite through Implementation ofN-(1-Naphthyl)ethylenediamine-Grafted Cellulose into a Paper-Based Device

Reported herein is the immobilization of N-(1-naphthyl)ethylenediamine (NED) on cellulose via an epichlorohydrin (ECH)-based covalent attachment and the implementation of the functionalized cellulose into an ultrasensitive, paper-based device for nitrite detection. The reported functionalization procedure resulted in a 12.9-fold higher functionalization density than the density that results from the previously reported procedures, and the subsequent device allows for nitrite detection limits in synthetic freshwater and real seawater of 0.26 and 0.22 μM, respectively. The sensor is efficient in a wide range of temperature, humidity, turbidity, and salinity conditions and has been successfully applied for nitrite detection in real water samples.