The intensity of this peak gradually increased with the increase in concentration of NADH at even higher concentration (Fig. ). Therefore, we believe, at higher concentration of NADH, the probe undergoes some extent of aggregation resulting in a new aggregation induced emission (AIE) in the present experimental condition. The increase in emission intensity was observed till the ratio was 1:30 (probe:NADH) (Fig. ). Beyond this, the resulting solution became turbid and quenching of fluorescence was observed.