This circuit realises a capacitance Multiplication by factor of 1+R1/R2.
To test this, The response to a pulse signal is compared against a simple 1st order RC circuit.
Where we can see that with the same capacitor value the response from the bottom circuit(OPAMP circuit) is slower due the reason that capacitor is multiplied by a factor 1+R1/R2.
So 1nF will manifest as 1nF × (1+10k/1k) = 11nF.
It comes with a series resistance of R1 || R2.
i.e. 10k ll 1k = 909.09 ~ 910 Ohm (0.91kOhm)
Proof :
https://drive.google.com/file/d/1Nk9ofnL8UgYVc6pKgPshCksqd_L8aqJc/view?usp=drivesdk
