Loading and Light Degradation Characteristics of Bt Toxin on Nanogoethite: A Potential Material for Controlling the Environmental Risk of Bt Toxin

Table 1

Insecticidal activity of the free toxin, goethite-toxin complexes, and powder of B. thuringiensis before and after ultraviolet irradiation.

Sample
	Before ultraviolet irradiation	After ultraviolet irradiation	Change
	μg/mL		%
Free toxin	10.00 ± 2.37	13.1 ± 3.02	31.0
Goethite-toxin	695.29 ± 70.31	6840.61 ± 840.35	883.8
Powder of B. thuringiensis	28.4 ± 3.40	36.2 ± 6.05	27.5

There were no mortalities with the mineral alone.
Lethal concentration to kill 50% of the larvae.
Change = [(LC₅₀ after ultraviolet irradiation − LC₅₀ before ultraviolet irradiation)/LC₅₀ before ultraviolet irradiation] × 100.